diff --git a/src/AuctionService/Consumers/AuctionCreatedFaultConsumer.cs b/src/AuctionService/Consumers/AuctionCreatedFaultConsumer.cs
index 054ff4a..2b75eb4 100644
--- a/src/AuctionService/Consumers/AuctionCreatedFaultConsumer.cs
+++ b/src/AuctionService/Consumers/AuctionCreatedFaultConsumer.cs
@@ -3,7 +3,7 @@
 
 namespace AuctionService.Consumers
 {
-    public class AuctionCreatedFaultConsumer : IConsumer<Fault<AuctionCreated>>
+    public sealed class AuctionCreatedFaultConsumer : IConsumer<Fault<AuctionCreated>>
     {
         public async Task Consume(ConsumeContext<Fault<AuctionCreated>> context)
         {
@@ -22,4 +22,4 @@ public async Task Consume(ConsumeContext<Fault<AuctionCreated>> context)
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Consumers/AuctionFinishedConsumer.cs b/src/AuctionService/Consumers/AuctionFinishedConsumer.cs
index 7061f3f..88a3745 100644
--- a/src/AuctionService/Consumers/AuctionFinishedConsumer.cs
+++ b/src/AuctionService/Consumers/AuctionFinishedConsumer.cs
@@ -5,7 +5,7 @@
 
 namespace AuctionService.Consumers
 {
-    public class AuctionFinishedConsumer(AuctionContext dbContext) : IConsumer<AuctionFinished>
+    public sealed class AuctionFinishedConsumer(AuctionContext dbContext) : IConsumer<AuctionFinished>
     {
         public async Task Consume(ConsumeContext<AuctionFinished> context)
         {
@@ -25,4 +25,4 @@ public async Task Consume(ConsumeContext<AuctionFinished> context)
             await dbContext.SaveChangesAsync();
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Consumers/BidPlacedConsumer.cs b/src/AuctionService/Consumers/BidPlacedConsumer.cs
index 6bdfeda..1e856e1 100644
--- a/src/AuctionService/Consumers/BidPlacedConsumer.cs
+++ b/src/AuctionService/Consumers/BidPlacedConsumer.cs
@@ -5,7 +5,7 @@
 
 namespace AuctionService.Consumers
 {
-    public class BidPlacedConsumer(AuctionContext dbContext) : IConsumer<BidPlaced>
+    public sealed class BidPlacedConsumer(AuctionContext dbContext) : IConsumer<BidPlaced>
     {
         public async Task Consume(ConsumeContext<BidPlaced> context)
         {
@@ -22,4 +22,4 @@ public async Task Consume(ConsumeContext<BidPlaced> context)
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Contracts/AuctionCreated.cs b/src/AuctionService/Contracts/AuctionCreated.cs
index 3b7789c..609b633 100644
--- a/src/AuctionService/Contracts/AuctionCreated.cs
+++ b/src/AuctionService/Contracts/AuctionCreated.cs
@@ -1,6 +1,6 @@
 namespace Contracts
 {
-    public class AuctionCreated
+    public sealed class AuctionCreated
     {
         public Guid Id { get; set; }
         public int ReservePrice { get; set; }
@@ -19,4 +19,4 @@ public class AuctionCreated
         public int Mileage { get; set; }
         public string ImageUrl { get; set; } = string.Empty;
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Contracts/AuctionDeleted.cs b/src/AuctionService/Contracts/AuctionDeleted.cs
index 6a7166f..9d44170 100644
--- a/src/AuctionService/Contracts/AuctionDeleted.cs
+++ b/src/AuctionService/Contracts/AuctionDeleted.cs
@@ -1,7 +1,7 @@
 namespace Contracts
 {
-    public class AuctionDeleted
+    public sealed class AuctionDeleted
     {
         public string? Id { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Contracts/AuctionFinished.cs b/src/AuctionService/Contracts/AuctionFinished.cs
index ee5c2ea..ef96b3c 100644
--- a/src/AuctionService/Contracts/AuctionFinished.cs
+++ b/src/AuctionService/Contracts/AuctionFinished.cs
@@ -1,6 +1,6 @@
 namespace AuctionService.Contracts
 {
-    public class AuctionFinished
+    public sealed class AuctionFinished
     {
         public bool ItemSold { get; set; }
         public string? AuctionId { get; set; }
@@ -8,4 +8,4 @@ public class AuctionFinished
         public string? Seller { get; set; }
         public int? Amount { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Contracts/AuctionUpdated.cs b/src/AuctionService/Contracts/AuctionUpdated.cs
index 89573dc..69a4f09 100644
--- a/src/AuctionService/Contracts/AuctionUpdated.cs
+++ b/src/AuctionService/Contracts/AuctionUpdated.cs
@@ -1,6 +1,6 @@
 namespace Contracts
 {
-    public class AuctionUpdated
+    public sealed class AuctionUpdated
     {
         public string? Id { get; set; }
         public string? Make { get; set; }
@@ -9,4 +9,4 @@ public class AuctionUpdated
         public string? Color { get; set; }
         public int Mileage { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Contracts/BidPlaced.cs b/src/AuctionService/Contracts/BidPlaced.cs
index bda31ae..5310878 100644
--- a/src/AuctionService/Contracts/BidPlaced.cs
+++ b/src/AuctionService/Contracts/BidPlaced.cs
@@ -1,6 +1,6 @@
 namespace AuctionService.Contracts
 {
-    public class BidPlaced
+    public sealed class BidPlaced
     {
         public string? Id { get; set; }
         public string? AuctionId { get; set; }
@@ -9,4 +9,4 @@ public class BidPlaced
         public int Amount { get; set; }
         public string? BidStatus { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Controllers/AuctionsController.cs b/src/AuctionService/Controllers/AuctionsController.cs
index 333a207..95b975b 100644
--- a/src/AuctionService/Controllers/AuctionsController.cs
+++ b/src/AuctionService/Controllers/AuctionsController.cs
@@ -11,7 +11,7 @@ namespace AuctionService.Controllers
 {
     [ApiController]
     [Route("api/[controller]")]
-    public class AuctionsController(IMapper mapper, IPublishEndpoint publishEndpoint, 
+    public sealed class AuctionsController(IMapper mapper, IPublishEndpoint publishEndpoint, 
         IAuctionRepository auctionRepository) : ControllerBase
     {
         [HttpGet]
@@ -90,4 +90,4 @@ public async Task<ActionResult> DeleteAuction(Guid id)
             return success ? Ok() : BadRequest("Could not update the database.");
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Data/AuctionContext.cs b/src/AuctionService/Data/AuctionContext.cs
index ed039e4..829a1b4 100644
--- a/src/AuctionService/Data/AuctionContext.cs
+++ b/src/AuctionService/Data/AuctionContext.cs
@@ -4,11 +4,11 @@
 
 namespace AuctionService.Data
 {
-    public class AuctionContext(DbContextOptions options) : DbContext(options)
+    public sealed class AuctionContext(DbContextOptions options) : DbContext(options)
     {
         public DbSet<Auction> Auctions { get; set; }
 
-        protected override void OnModelCreating(ModelBuilder modelBuilder)
+        protected sealed override void OnModelCreating(ModelBuilder modelBuilder)
         {
             base.OnModelCreating(modelBuilder);
 
@@ -17,4 +17,4 @@ protected override void OnModelCreating(ModelBuilder modelBuilder)
             modelBuilder.AddOutboxStateEntity();
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Data/DbInitializer.cs b/src/AuctionService/Data/DbInitializer.cs
index 67166e9..7556bf9 100644
--- a/src/AuctionService/Data/DbInitializer.cs
+++ b/src/AuctionService/Data/DbInitializer.cs
@@ -3,7 +3,7 @@
 
 namespace AuctionService.Data
 {
-    public class DbInitializer
+    public sealed class DbInitializer
     {
         public static void InitDb(WebApplication app)
         {
@@ -210,4 +210,4 @@ public static List<Auction> GetDbAuctions() =>
                 }
             ];
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Dtos/AuctionDto.cs b/src/AuctionService/Dtos/AuctionDto.cs
index 0c3f637..20b4736 100644
--- a/src/AuctionService/Dtos/AuctionDto.cs
+++ b/src/AuctionService/Dtos/AuctionDto.cs
@@ -1,6 +1,6 @@
 namespace AuctionService.Dtos
 {
-    public class AuctionDto
+    public sealed class AuctionDto
     {
         public Guid Id { get; set; }
         public int ReservePrice { get; set; }
@@ -19,4 +19,4 @@ public class AuctionDto
         public int Mileage { get; set; }
         public string ImageUrl { get; set; } = string.Empty;
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Dtos/CreateAuctionDto.cs b/src/AuctionService/Dtos/CreateAuctionDto.cs
index 575456d..ed975dd 100644
--- a/src/AuctionService/Dtos/CreateAuctionDto.cs
+++ b/src/AuctionService/Dtos/CreateAuctionDto.cs
@@ -2,7 +2,7 @@
 
 namespace AuctionService.Dtos
 {
-    public class CreateAuctionDto
+    public sealed class CreateAuctionDto
     {
         [Required]
         public string? Make { get; set; }
@@ -28,4 +28,4 @@ public class CreateAuctionDto
         [Required]
         public DateTime AuctionEnd { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Dtos/UpdateAuctionDto.cs b/src/AuctionService/Dtos/UpdateAuctionDto.cs
index 4d76e19..05b3475 100644
--- a/src/AuctionService/Dtos/UpdateAuctionDto.cs
+++ b/src/AuctionService/Dtos/UpdateAuctionDto.cs
@@ -1,6 +1,6 @@
 namespace AuctionService.Dtos
 {
-    public class UpdateAuctionDto
+    public sealed class UpdateAuctionDto
     {
         public string? Make { get; set; }
         public string? Model { get; set; }
@@ -8,4 +8,4 @@ public class UpdateAuctionDto
         public string? Color { get; set; }
         public int? Mileage { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Entities/Auction.cs b/src/AuctionService/Entities/Auction.cs
index 0d7c6ab..24bc3be 100644
--- a/src/AuctionService/Entities/Auction.cs
+++ b/src/AuctionService/Entities/Auction.cs
@@ -1,6 +1,6 @@
 namespace AuctionService.Entities
 {
-    public class Auction
+    public sealed class Auction
     {
         public Guid Id { get; set; }
         public int ReservePrice { get; set; }
@@ -16,4 +16,4 @@ public class Auction
 
         public bool HasReservePrice() => ReservePrice > 0;
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Entities/Item.cs b/src/AuctionService/Entities/Item.cs
index d407c25..1649223 100644
--- a/src/AuctionService/Entities/Item.cs
+++ b/src/AuctionService/Entities/Item.cs
@@ -3,7 +3,7 @@
 namespace AuctionService.Entities
 {
     [Table("Items")]
-    public class Item
+    public sealed class Item
     {
         public Guid Id { get; set; }
         public string Make { get; set; } = string.Empty;
@@ -17,4 +17,4 @@ public class Item
         public Auction? Auction { get; set; }
         public Guid AuctionId { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Entities/Status.cs b/src/AuctionService/Entities/Status.cs
index 988fdf3..46d2302 100644
--- a/src/AuctionService/Entities/Status.cs
+++ b/src/AuctionService/Entities/Status.cs
@@ -6,4 +6,4 @@ public enum Status
         Finished,
         ReserveNotMet
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Program.cs b/src/AuctionService/Program.cs
index 2f9d692..fd9452b 100644
--- a/src/AuctionService/Program.cs
+++ b/src/AuctionService/Program.cs
@@ -79,4 +79,4 @@
 /// <summary>
 /// Represents the entry point for the AuctionService program.
 /// </summary>
-public partial class Program {}
+public sealed partial class Program {}
diff --git a/src/AuctionService/Repositories/AuctionRepository.cs b/src/AuctionService/Repositories/AuctionRepository.cs
index 1e51f1c..b72eeb3 100644
--- a/src/AuctionService/Repositories/AuctionRepository.cs
+++ b/src/AuctionService/Repositories/AuctionRepository.cs
@@ -7,7 +7,7 @@
 
 namespace AuctionService.Repositories
 {
-    public class AuctionRepository(AuctionContext context, IMapper mapper) : IAuctionRepository
+    public sealed class AuctionRepository(AuctionContext context, IMapper mapper) : IAuctionRepository
     {
         public void AddAuction(Auction request) =>
             context.Auctions.Add(request);
@@ -36,4 +36,4 @@ public async Task<List<AuctionDto>> GetAuctionsAsync(string request)
 
         public async Task<bool> SaveChangesAsync() => await context.SaveChangesAsync() > 0;
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Repositories/IAuctionRepository.cs b/src/AuctionService/Repositories/IAuctionRepository.cs
index f78492b..4eb8201 100644
--- a/src/AuctionService/Repositories/IAuctionRepository.cs
+++ b/src/AuctionService/Repositories/IAuctionRepository.cs
@@ -12,4 +12,4 @@ public interface IAuctionRepository
         void RemoveAuction(Auction request);
         Task<bool> SaveChangesAsync();
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/RequestHelpers/MappingProfiles.cs b/src/AuctionService/RequestHelpers/MappingProfiles.cs
index 4da2a23..0b9d516 100644
--- a/src/AuctionService/RequestHelpers/MappingProfiles.cs
+++ b/src/AuctionService/RequestHelpers/MappingProfiles.cs
@@ -5,7 +5,7 @@
 
 namespace AuctionService.RequestHelpers
 {
-    public class MappingProfiles : Profile
+    public sealed class MappingProfiles : Profile
     {
         public MappingProfiles()
         {
@@ -22,4 +22,4 @@ public MappingProfiles()
             CreateMap<Item, AuctionUpdated>();
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/AuctionService/Services/GrpcAuctionService.cs b/src/AuctionService/Services/GrpcAuctionService.cs
index 4fa4d54..4b058ba 100644
--- a/src/AuctionService/Services/GrpcAuctionService.cs
+++ b/src/AuctionService/Services/GrpcAuctionService.cs
@@ -3,9 +3,9 @@
 
 namespace AuctionService.Services
 {
-    public class GrpcAuctionService(AuctionContext dbContext) : GrpcAuction.GrpcAuctionBase
+    public sealed class GrpcAuctionService(AuctionContext dbContext) : GrpcAuction.GrpcAuctionBase
     {
-        public override async Task<GrpcAuctionResponse> GetAuction(GetAuctionRequest request, ServerCallContext context)
+        public sealed override async Task<GrpcAuctionResponse> GetAuction(GetAuctionRequest request, ServerCallContext context)
         {
             Console.WriteLine("==> Recieved gRPC request for auction");
 
@@ -26,4 +26,4 @@ public override async Task<GrpcAuctionResponse> GetAuction(GetAuctionRequest req
             return response;
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/BiddingService/Consumers/AuctionCreatedConsumer.cs b/src/BiddingService/Consumers/AuctionCreatedConsumer.cs
index 83a9e37..292ff59 100644
--- a/src/BiddingService/Consumers/AuctionCreatedConsumer.cs
+++ b/src/BiddingService/Consumers/AuctionCreatedConsumer.cs
@@ -5,7 +5,7 @@
 
 namespace BiddingService.Consumers
 {
-    public class AuctionCreatedConsumer : IConsumer<AuctionCreated>
+    public sealed class AuctionCreatedConsumer : IConsumer<AuctionCreated>
     {
         public async Task Consume(ConsumeContext<AuctionCreated> context)
         {
@@ -20,4 +20,4 @@ public async Task Consume(ConsumeContext<AuctionCreated> context)
             await auction.SaveAsync();
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/BiddingService/Contracts/AuctionCreated.cs b/src/BiddingService/Contracts/AuctionCreated.cs
index 8779564..30f4690 100644
--- a/src/BiddingService/Contracts/AuctionCreated.cs
+++ b/src/BiddingService/Contracts/AuctionCreated.cs
@@ -1,6 +1,6 @@
 namespace BiddingService.Contracts
 {
-    public class AuctionCreated
+    public sealed class AuctionCreated
     {
         public Guid Id { get; set; }
         public int ReservePrice { get; set; }
@@ -19,4 +19,4 @@ public class AuctionCreated
         public int Mileage { get; set; }
         public string ImageUrl { get; set; } = string.Empty;
     }
-}
\ No newline at end of file
+}
diff --git a/src/BiddingService/Contracts/AuctionDeleted.cs b/src/BiddingService/Contracts/AuctionDeleted.cs
index f6c1305..a835f7b 100644
--- a/src/BiddingService/Contracts/AuctionDeleted.cs
+++ b/src/BiddingService/Contracts/AuctionDeleted.cs
@@ -1,7 +1,7 @@
 namespace BiddingService.Contracts
 {
-    public class AuctionDeleted
+    public sealed class AuctionDeleted
     {
         public string? Id { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/BiddingService/Contracts/AuctionFinished.cs b/src/BiddingService/Contracts/AuctionFinished.cs
index cb8bac3..cc996d7 100644
--- a/src/BiddingService/Contracts/AuctionFinished.cs
+++ b/src/BiddingService/Contracts/AuctionFinished.cs
@@ -1,6 +1,6 @@
 namespace BiddingService.Contracts
 {
-    public class AuctionFinished
+    public sealed class AuctionFinished
     {
         public bool ItemSold { get; set; }
         public string? AuctionId { get; set; }
@@ -8,4 +8,4 @@ public class AuctionFinished
         public string? Seller { get; set; }
         public int? Amount { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/BiddingService/Contracts/AuctionUpdated.cs b/src/BiddingService/Contracts/AuctionUpdated.cs
index c4a037b..1d65f55 100644
--- a/src/BiddingService/Contracts/AuctionUpdated.cs
+++ b/src/BiddingService/Contracts/AuctionUpdated.cs
@@ -1,6 +1,6 @@
 namespace BiddingService.Contracts
 {
-    public class AuctionUpdated
+    public sealed class AuctionUpdated
     {
         public string? Id { get; set; }
         public string? Make { get; set; }
@@ -9,4 +9,4 @@ public class AuctionUpdated
         public string? Color { get; set; }
         public int Mileage { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/BiddingService/Contracts/BidPlaced.cs b/src/BiddingService/Contracts/BidPlaced.cs
index 5608ace..8bd015c 100644
--- a/src/BiddingService/Contracts/BidPlaced.cs
+++ b/src/BiddingService/Contracts/BidPlaced.cs
@@ -1,6 +1,6 @@
 namespace BiddingService.Contracts
 {
-    public class BidPlaced
+    public sealed class BidPlaced
     {
         public string? Id { get; set; }
         public string? AuctionId { get; set; }
@@ -9,4 +9,4 @@ public class BidPlaced
         public int Amount { get; set; }
         public string? BidStatus { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/BiddingService/Controllers/BidsController.cs b/src/BiddingService/Controllers/BidsController.cs
index 85b4c46..7144018 100644
--- a/src/BiddingService/Controllers/BidsController.cs
+++ b/src/BiddingService/Controllers/BidsController.cs
@@ -12,7 +12,7 @@ namespace BiddingService.Controllers
 {
     [ApiController]
     [Route("api/[controller]")]
-    public class BidsController(IMapper mapper, IPublishEndpoint publishEndpoint, 
+    public sealed class BidsController(IMapper mapper, IPublishEndpoint publishEndpoint, 
         GrpcAuctionClient grpcClient) : ControllerBase
     {
         [HttpPost, Authorize] 
@@ -73,4 +73,4 @@ public async Task<ActionResult<List<BidDto>>> GetBidsForAuction(string auctionId
             return bids.Select(mapper.Map<BidDto>).ToList();
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/BiddingService/Dtos/BidDto.cs b/src/BiddingService/Dtos/BidDto.cs
index 32473e2..c863b8c 100644
--- a/src/BiddingService/Dtos/BidDto.cs
+++ b/src/BiddingService/Dtos/BidDto.cs
@@ -1,6 +1,6 @@
 namespace BiddingService.Dtos
 {
-    public class BidDto
+    public sealed class BidDto
     {
         public string? Id { get; set; }
         public string? AuctionId { get; set; }
@@ -9,4 +9,4 @@ public class BidDto
         public int Amount { get; set; }
         public string? BidStatus { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/BiddingService/Models/Auction.cs b/src/BiddingService/Models/Auction.cs
index e756fad..1120532 100644
--- a/src/BiddingService/Models/Auction.cs
+++ b/src/BiddingService/Models/Auction.cs
@@ -2,11 +2,11 @@
 
 namespace BiddingService.Models
 {
-    public class Auction : Entity
+    public sealed class Auction : Entity
     {
         public DateTime AuctionEnd { get; set; }
         public string? Seller { get; set; }
         public int ReservePrice { get; set; }
         public bool Finished { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/BiddingService/Models/Bid.cs b/src/BiddingService/Models/Bid.cs
index dd38fea..6040245 100644
--- a/src/BiddingService/Models/Bid.cs
+++ b/src/BiddingService/Models/Bid.cs
@@ -2,7 +2,7 @@
 
 namespace BiddingService.Models
 {
-    public class Bid : Entity
+    public sealed class Bid : Entity
     {
         public string? AuctionId { get; set; }
         public string? Bidder { get; set; }
@@ -10,4 +10,4 @@ public class Bid : Entity
         public int Amount { get; set; }
         public BidStatus BidStatus { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/BiddingService/Models/BidStatus.cs b/src/BiddingService/Models/BidStatus.cs
index 7d8bf2b..397bee7 100644
--- a/src/BiddingService/Models/BidStatus.cs
+++ b/src/BiddingService/Models/BidStatus.cs
@@ -7,4 +7,4 @@ public enum BidStatus
         TooLow,
         Finished
     }
-}
\ No newline at end of file
+}
diff --git a/src/BiddingService/RequestHelpers/MappingProfiles.cs b/src/BiddingService/RequestHelpers/MappingProfiles.cs
index d007703..8e956c4 100644
--- a/src/BiddingService/RequestHelpers/MappingProfiles.cs
+++ b/src/BiddingService/RequestHelpers/MappingProfiles.cs
@@ -5,7 +5,7 @@
 
 namespace BiddingService.RequestHelpers
 {
-    public class MappingProfiles : Profile
+    public sealed class MappingProfiles : Profile
     {
         public MappingProfiles()
         {
@@ -13,4 +13,4 @@ public MappingProfiles()
             CreateMap<Bid, BidPlaced>();
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/BiddingService/Services/CheckAuctionFinished.cs b/src/BiddingService/Services/CheckAuctionFinished.cs
index d10836f..1949460 100644
--- a/src/BiddingService/Services/CheckAuctionFinished.cs
+++ b/src/BiddingService/Services/CheckAuctionFinished.cs
@@ -5,9 +5,10 @@
 
 namespace BiddingService.Services
 {
-    public class CheckAuctionFinished(ILogger<CheckAuctionFinished> logger, IServiceProvider services) : BackgroundService
+    public sealed class CheckAuctionFinished(ILogger<CheckAuctionFinished> logger, 
+        IServiceProvider services) : BackgroundService
     {
-        protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+        protected sealed override async Task ExecuteAsync(CancellationToken stoppingToken)
         {
             logger.LogInformation("Starting check for finished auctions");
 
@@ -57,4 +58,4 @@ await endpoint.Publish(new AuctionFinished
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/BiddingService/Services/GrpcAuctionClient.cs b/src/BiddingService/Services/GrpcAuctionClient.cs
index 10edf7e..3b5db22 100644
--- a/src/BiddingService/Services/GrpcAuctionClient.cs
+++ b/src/BiddingService/Services/GrpcAuctionClient.cs
@@ -4,7 +4,7 @@
 
 namespace BiddingService.Services
 {
-    public class GrpcAuctionClient(ILogger<GrpcAuctionClient> logger, IConfiguration config)
+    public sealed class GrpcAuctionClient(ILogger<GrpcAuctionClient> logger, IConfiguration config)
     {
         public Auction GetAuction(string id)
         {
@@ -37,4 +37,4 @@ public Auction GetAuction(string id)
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/IdentityService/Config.cs b/src/IdentityService/Config.cs
index ecfe36d..acbc4ae 100644
--- a/src/IdentityService/Config.cs
+++ b/src/IdentityService/Config.cs
@@ -1,47 +1,48 @@
 using Duende.IdentityServer.Models;
 
-namespace IdentityService;
-
-public static class Config
+namespace IdentityService
 {
-    public static IEnumerable<IdentityResource> IdentityResources =>
-        [
-            new IdentityResources.OpenId(),
-            new IdentityResources.Profile(),
-        ];
+    public static class Config
+    {
+        public static IEnumerable<IdentityResource> IdentityResources =>
+            [
+                new IdentityResources.OpenId(),
+                new IdentityResources.Profile(),
+            ];
 
-    public static IEnumerable<ApiScope> ApiScopes =>
-        [
-            new("auctionApp", "Auction app full access"),
-        ];
+        public static IEnumerable<ApiScope> ApiScopes =>
+            [
+                new("auctionApp", "Auction app full access"),
+            ];
 
-    public static IEnumerable<Client> Clients(IConfiguration config) =>
-        [
-            // interactive client using code flow + pkce
-            new()
-            {
-                ClientId = "postman",
-                ClientName = "Postman",
-                AllowedScopes = { "openid", "profile", "auctionApp" },
-                RedirectUris = { "https://www.getpostman.com/oauth2/callback" },
-                ClientSecrets =
-                [
-                    new Secret("NotASecret".Sha256())
-                ],
-                AllowedGrantTypes = { GrantType.ResourceOwnerPassword }
-            },
-            new()
-            {
-                ClientId = "nextApp",
-                ClientName = "nextApp",
-                ClientSecrets = { new Secret("secret".Sha256())},
-                AllowedGrantTypes = GrantTypes.CodeAndClientCredentials,
-                RequirePkce = false,
-                RedirectUris = { config["ClientApp"] + "/api/auth/callback/id-server" },
-                AllowOfflineAccess = true,
-                AllowedScopes = { "openid", "profile", "auctionApp" },
-                AccessTokenLifetime = 3600*24*30,
-                AlwaysIncludeUserClaimsInIdToken = true
-            }
-        ];
+        public static IEnumerable<Client> Clients(IConfiguration config) =>
+            [
+                // interactive client using code flow + pkce
+                new()
+                {
+                    ClientId = "postman",
+                    ClientName = "Postman",
+                    AllowedScopes = { "openid", "profile", "auctionApp" },
+                    RedirectUris = { "https://www.getpostman.com/oauth2/callback" },
+                    ClientSecrets =
+                    [
+                        new Secret("NotASecret".Sha256())
+                    ],
+                    AllowedGrantTypes = { GrantType.ResourceOwnerPassword }
+                },
+                new()
+                {
+                    ClientId = "nextApp",
+                    ClientName = "nextApp",
+                    ClientSecrets = { new Secret("secret".Sha256())},
+                    AllowedGrantTypes = GrantTypes.CodeAndClientCredentials,
+                    RequirePkce = false,
+                    RedirectUris = { config["ClientApp"] + "/api/auth/callback/id-server" },
+                    AllowOfflineAccess = true,
+                    AllowedScopes = { "openid", "profile", "auctionApp" },
+                    AccessTokenLifetime = 3600*24*30,
+                    AlwaysIncludeUserClaimsInIdToken = true
+                }
+            ];
+    }
 }
diff --git a/src/IdentityService/Data/ApplicationDbContext.cs b/src/IdentityService/Data/ApplicationDbContext.cs
index 00824bd..3196d9b 100644
--- a/src/IdentityService/Data/ApplicationDbContext.cs
+++ b/src/IdentityService/Data/ApplicationDbContext.cs
@@ -2,15 +2,17 @@
 using Microsoft.EntityFrameworkCore;
 using IdentityService.Models;
 
-namespace IdentityService.Data;
-
-public class ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) : IdentityDbContext<ApplicationUser>(options)
+namespace IdentityService.Data
 {
-    protected override void OnModelCreating(ModelBuilder builder)
+    public sealed class ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) 
+        : IdentityDbContext<ApplicationUser>(options)
     {
-        base.OnModelCreating(builder);
-        // Customize the ASP.NET Identity model and override the defaults if needed.
-        // For example, you can rename the ASP.NET Identity table names and more.
-        // Add your customizations after calling base.OnModelCreating(builder);
+        protected sealed override void OnModelCreating(ModelBuilder builder)
+        {
+            base.OnModelCreating(builder);
+            // Customize the ASP.NET Identity model and override the defaults if needed.
+            // For example, you can rename the ASP.NET Identity table names and more.
+            // Add your customizations after calling base.OnModelCreating(builder);
+        }
     }
 }
diff --git a/src/IdentityService/HostingExtensions.cs b/src/IdentityService/HostingExtensions.cs
index e416fc3..bcde47c 100644
--- a/src/IdentityService/HostingExtensions.cs
+++ b/src/IdentityService/HostingExtensions.cs
@@ -5,69 +5,70 @@
 using Microsoft.EntityFrameworkCore;
 using Serilog;
 
-namespace IdentityService;
-
-internal static class HostingExtensions
+namespace IdentityService
 {
-    public static WebApplication ConfigureServices(this WebApplicationBuilder builder)
+    internal static class HostingExtensions
     {
-        builder.Services.AddRazorPages();
+        public static WebApplication ConfigureServices(this WebApplicationBuilder builder)
+        {
+            builder.Services.AddRazorPages();
 
-        builder.Services.AddDbContext<ApplicationDbContext>(options =>
-            options.UseNpgsql(builder.Configuration.GetConnectionString("Default")));
+            builder.Services.AddDbContext<ApplicationDbContext>(options =>
+                options.UseNpgsql(builder.Configuration.GetConnectionString("Default")));
 
-        builder.Services.AddIdentity<ApplicationUser, IdentityRole>()
-            .AddEntityFrameworkStores<ApplicationDbContext>()
-            .AddDefaultTokenProviders();
+            builder.Services.AddIdentity<ApplicationUser, IdentityRole>()
+                .AddEntityFrameworkStores<ApplicationDbContext>()
+                .AddDefaultTokenProviders();
 
-        builder.Services
-            .AddIdentityServer(options =>
-            {
-                options.Events.RaiseErrorEvents = true;
-                options.Events.RaiseInformationEvents = true;
-                options.Events.RaiseFailureEvents = true;
-                options.Events.RaiseSuccessEvents = true;
-                
-                // Sets the issuer URI to identity-svc when running in Docker.
-                if (builder.Environment.IsEnvironment("Docker"))
-                    options.IssuerUri = "identity-svc";
+            builder.Services
+                .AddIdentityServer(options =>
+                {
+                    options.Events.RaiseErrorEvents = true;
+                    options.Events.RaiseInformationEvents = true;
+                    options.Events.RaiseFailureEvents = true;
+                    options.Events.RaiseSuccessEvents = true;
+                    
+                    // Sets the issuer URI to identity-svc when running in Docker.
+                    if (builder.Environment.IsEnvironment("Docker"))
+                        options.IssuerUri = "identity-svc";
 
-                // see https://docs.duendesoftware.com/identityserver/v6/fundamentals/resources/
-                // options.EmitStaticAudienceClaim = true;
-            })
-            .AddInMemoryIdentityResources(Config.IdentityResources)
-            .AddInMemoryApiScopes(Config.ApiScopes)
-            .AddInMemoryClients(Config.Clients(builder.Configuration))
-            .AddAspNetIdentity<ApplicationUser>()
-            .AddProfileService<CustomProfileService>();
+                    // see https://docs.duendesoftware.com/identityserver/v6/fundamentals/resources/
+                    // options.EmitStaticAudienceClaim = true;
+                })
+                .AddInMemoryIdentityResources(Config.IdentityResources)
+                .AddInMemoryApiScopes(Config.ApiScopes)
+                .AddInMemoryClients(Config.Clients(builder.Configuration))
+                .AddAspNetIdentity<ApplicationUser>()
+                .AddProfileService<CustomProfileService>();
 
-        builder.Services.ConfigureApplicationCookie(options => 
-        {
-            options.Cookie.SameSite = SameSiteMode.Lax;
-        });
-        
-        builder.Services.AddAuthentication();
+            builder.Services.ConfigureApplicationCookie(options => 
+            {
+                options.Cookie.SameSite = SameSiteMode.Lax;
+            });
+            
+            builder.Services.AddAuthentication();
 
-        return builder.Build();
-    }
-    
-    public static WebApplication ConfigurePipeline(this WebApplication app)
-    { 
-        app.UseSerilogRequestLogging();
-    
-        if (app.Environment.IsDevelopment())
-        {
-            app.UseDeveloperExceptionPage();
+            return builder.Build();
         }
-
-        app.UseStaticFiles();
-        app.UseRouting();
-        app.UseIdentityServer();
-        app.UseAuthorization();
         
-        app.MapRazorPages()
-            .RequireAuthorization();
+        public static WebApplication ConfigurePipeline(this WebApplication app)
+        { 
+            app.UseSerilogRequestLogging();
+        
+            if (app.Environment.IsDevelopment())
+            {
+                app.UseDeveloperExceptionPage();
+            }
+
+            app.UseStaticFiles();
+            app.UseRouting();
+            app.UseIdentityServer();
+            app.UseAuthorization();
+            
+            app.MapRazorPages()
+                .RequireAuthorization();
 
-        return app;
+            return app;
+        }
     }
-}
\ No newline at end of file
+}
diff --git a/src/IdentityService/Models/ApplicationUser.cs b/src/IdentityService/Models/ApplicationUser.cs
index 5156969..2ca004c 100644
--- a/src/IdentityService/Models/ApplicationUser.cs
+++ b/src/IdentityService/Models/ApplicationUser.cs
@@ -4,9 +4,9 @@
 
 using Microsoft.AspNetCore.Identity;
 
-namespace IdentityService.Models;
-
-// Add profile data for application users by adding properties to the ApplicationUser class
-public class ApplicationUser : IdentityUser
+namespace IdentityService.Models
 {
+
+    // Add profile data for application users by adding properties to the ApplicationUser class
+    public sealed class ApplicationUser : IdentityUser { }
 }
diff --git a/src/IdentityService/Program.cs b/src/IdentityService/Program.cs
index eebdc3d..abd89bf 100644
--- a/src/IdentityService/Program.cs
+++ b/src/IdentityService/Program.cs
@@ -41,4 +41,4 @@
 {
     Log.Information("Shut down complete");
     Log.CloseAndFlush();
-}
\ No newline at end of file
+}
diff --git a/src/IdentityService/SeedData.cs b/src/IdentityService/SeedData.cs
index 9fb7767..d5e8696 100644
--- a/src/IdentityService/SeedData.cs
+++ b/src/IdentityService/SeedData.cs
@@ -5,64 +5,77 @@
 using Microsoft.EntityFrameworkCore;
 using Serilog;
 
-namespace IdentityService;
-
-public class SeedData
+namespace IdentityService
 {
-    public static void EnsureSeedData(WebApplication app)
+    public sealed class SeedData
     {
-        using IServiceScope scope = app.Services.GetRequiredService<IServiceScopeFactory>().CreateScope();
-        ApplicationDbContext context = scope.ServiceProvider.GetService<ApplicationDbContext>();
-        context.Database.Migrate();
+        public static void EnsureSeedData(WebApplication app)
+        {
+            using IServiceScope scope = app.Services.GetRequiredService<IServiceScopeFactory>().CreateScope();
+            ApplicationDbContext context = scope.ServiceProvider.GetService<ApplicationDbContext>();
+            context.Database.Migrate();
 
-        UserManager<ApplicationUser> userMgr = scope.ServiceProvider.GetRequiredService<UserManager<ApplicationUser>>();
+            UserManager<ApplicationUser> userMgr = scope.ServiceProvider.GetRequiredService<UserManager<ApplicationUser>>();
 
-        if (userMgr.Users.Any()) return;
+            if (userMgr.Users.Any()) return;
 
-        ApplicationUser alice = userMgr.FindByNameAsync("alice").Result;
-        if (alice is null)
-        {
-            alice = new ApplicationUser
+            ApplicationUser alice = userMgr.FindByNameAsync("alice").Result;
+            if (alice is null)
             {
-                UserName = "alice",
-                Email = "AliceSmith@email.com",
-                EmailConfirmed = true,
-            };
-            IdentityResult result = userMgr.CreateAsync(alice, "Pass123$").Result;
-            if (!result.Succeeded)
-                throw new Exception(result.Errors.First().Description);
+                alice = new ApplicationUser
+                {
+                    UserName = "alice",
+                    Email = "AliceSmith@email.com",
+                    EmailConfirmed = true,
+                };
+                IdentityResult result = userMgr.CreateAsync(alice, "Pass123$").Result;
+                if (!result.Succeeded)
+                {
+                    throw new Exception(result.Errors.First().Description);
+                }
 
-            result = userMgr.AddClaimsAsync(alice, [
-                new(JwtClaimTypes.Name, "Alice Smith"),
-            ]).Result;
-            if (!result.Succeeded)
-                throw new Exception(result.Errors.First().Description);
-            Log.Debug("alice created");
-        }
-        else
-            Log.Debug("alice already exists");
+                result = userMgr.AddClaimsAsync(alice, [
+                    new(JwtClaimTypes.Name, "Alice Smith"),
+                ]).Result;
+                if (!result.Succeeded)
+                {
+                    throw new Exception(result.Errors.First().Description);
+                }
+                Log.Debug("alice created");
+            }
+            else
+            {
+                Log.Debug("alice already exists");
+            }
 
-        ApplicationUser bob = userMgr.FindByNameAsync("bob").Result;
-        if (bob is null)
-        {
-            bob = new ApplicationUser
+            ApplicationUser bob = userMgr.FindByNameAsync("bob").Result;
+            if (bob is null)
             {
-                UserName = "bob",
-                Email = "BobSmith@email.com",
-                EmailConfirmed = true
-            };
-            IdentityResult result = userMgr.CreateAsync(bob, "Pass123$").Result;
-            if (!result.Succeeded)
-                throw new Exception(result.Errors.First().Description);
+                bob = new ApplicationUser
+                {
+                    UserName = "bob",
+                    Email = "BobSmith@email.com",
+                    EmailConfirmed = true
+                };
+                IdentityResult result = userMgr.CreateAsync(bob, "Pass123$").Result;
+                if (!result.Succeeded)
+                {
+                    throw new Exception(result.Errors.First().Description);
+                }
 
-            result = userMgr.AddClaimsAsync(bob, [
-                new(JwtClaimTypes.Name, "Bob Smith")
-            ]).Result;
-            if (!result.Succeeded)
-                throw new Exception(result.Errors.First().Description);
-            Log.Debug("bob created");
+                result = userMgr.AddClaimsAsync(bob, [
+                    new(JwtClaimTypes.Name, "Bob Smith")
+                ]).Result;
+                if (!result.Succeeded)
+                {
+                    throw new Exception(result.Errors.First().Description);
+                }
+                Log.Debug("bob created");
+            }
+            else
+            {
+                Log.Debug("bob already exists");
+            }
         }
-        else
-            Log.Debug("bob already exists");
     }
-}
\ No newline at end of file
+}
diff --git a/src/IdentityService/Services/CustomProfileService.cs b/src/IdentityService/Services/CustomProfileService.cs
index 1f0136b..306e416 100644
--- a/src/IdentityService/Services/CustomProfileService.cs
+++ b/src/IdentityService/Services/CustomProfileService.cs
@@ -7,7 +7,7 @@
 
 namespace IdentityService.Services
 {
-    public class CustomProfileService(UserManager<ApplicationUser> userManager) : IProfileService
+    public sealed class CustomProfileService(UserManager<ApplicationUser> userManager) : IProfileService
     {
         public async Task GetProfileDataAsync(ProfileDataRequestContext context)
         {
diff --git a/src/NotificationService/Consumers/AuctionCreatedConsumer.cs b/src/NotificationService/Consumers/AuctionCreatedConsumer.cs
index d607556..cabc0ef 100644
--- a/src/NotificationService/Consumers/AuctionCreatedConsumer.cs
+++ b/src/NotificationService/Consumers/AuctionCreatedConsumer.cs
@@ -1,6 +1,6 @@
 namespace NotificationService.Consumers
 {
-    public class AuctionCreatedConsumer(IHubContext<NotificationHub> hubContext) : IConsumer<AuctionCreated>
+    public sealed class AuctionCreatedConsumer(IHubContext<NotificationHub> hubContext) : IConsumer<AuctionCreated>
     {
         public async Task Consume(ConsumeContext<AuctionCreated> context)
         {
@@ -9,4 +9,4 @@ public async Task Consume(ConsumeContext<AuctionCreated> context)
             await hubContext.Clients.All.SendAsync("AuctionCreated", context.Message);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/NotificationService/Consumers/AuctionFinishedConsumer.cs b/src/NotificationService/Consumers/AuctionFinishedConsumer.cs
index 6ecec3d..8ffc788 100644
--- a/src/NotificationService/Consumers/AuctionFinishedConsumer.cs
+++ b/src/NotificationService/Consumers/AuctionFinishedConsumer.cs
@@ -1,6 +1,6 @@
 namespace NotificationService.Consumers
 {
-    public class AuctionFinishedConsumer(IHubContext<NotificationHub> hubContext) : IConsumer<AuctionFinished>
+    public sealed class AuctionFinishedConsumer(IHubContext<NotificationHub> hubContext) : IConsumer<AuctionFinished>
     {
         public async Task Consume(ConsumeContext<AuctionFinished> context)
         {
@@ -9,4 +9,4 @@ public async Task Consume(ConsumeContext<AuctionFinished> context)
             await hubContext.Clients.All.SendAsync("AuctionFinished", context.Message);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/NotificationService/Consumers/BidPlacedConsumer.cs b/src/NotificationService/Consumers/BidPlacedConsumer.cs
index 858e5ed..1ba726b 100644
--- a/src/NotificationService/Consumers/BidPlacedConsumer.cs
+++ b/src/NotificationService/Consumers/BidPlacedConsumer.cs
@@ -1,6 +1,6 @@
 namespace NotificationService.Consumers
 {
-    public class BidPlacedConsumer(IHubContext<NotificationHub> hubContext) : IConsumer<BidPlaced>
+    public sealed class BidPlacedConsumer(IHubContext<NotificationHub> hubContext) : IConsumer<BidPlaced>
     {
         public async Task Consume(ConsumeContext<BidPlaced> context)
         {
@@ -9,4 +9,4 @@ public async Task Consume(ConsumeContext<BidPlaced> context)
             await hubContext.Clients.All.SendAsync("BidPlaced", context.Message);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/NotificationService/Contracts/AuctionCreated.cs b/src/NotificationService/Contracts/AuctionCreated.cs
index 3b7789c..609b633 100644
--- a/src/NotificationService/Contracts/AuctionCreated.cs
+++ b/src/NotificationService/Contracts/AuctionCreated.cs
@@ -1,6 +1,6 @@
 namespace Contracts
 {
-    public class AuctionCreated
+    public sealed class AuctionCreated
     {
         public Guid Id { get; set; }
         public int ReservePrice { get; set; }
@@ -19,4 +19,4 @@ public class AuctionCreated
         public int Mileage { get; set; }
         public string ImageUrl { get; set; } = string.Empty;
     }
-}
\ No newline at end of file
+}
diff --git a/src/NotificationService/Contracts/AuctionDeleted.cs b/src/NotificationService/Contracts/AuctionDeleted.cs
index 6a7166f..9d44170 100644
--- a/src/NotificationService/Contracts/AuctionDeleted.cs
+++ b/src/NotificationService/Contracts/AuctionDeleted.cs
@@ -1,7 +1,7 @@
 namespace Contracts
 {
-    public class AuctionDeleted
+    public sealed class AuctionDeleted
     {
         public string? Id { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/NotificationService/Contracts/AuctionFinished.cs b/src/NotificationService/Contracts/AuctionFinished.cs
index 336b932..a29e8bf 100644
--- a/src/NotificationService/Contracts/AuctionFinished.cs
+++ b/src/NotificationService/Contracts/AuctionFinished.cs
@@ -1,6 +1,6 @@
 namespace Contracts
 {
-    public class AuctionFinished
+    public sealed class AuctionFinished
     {
         public bool ItemSold { get; set; }
         public string? AuctionId { get; set; }
@@ -8,4 +8,4 @@ public class AuctionFinished
         public string? Seller { get; set; }
         public int? Amount { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/NotificationService/Contracts/AuctionUpdated.cs b/src/NotificationService/Contracts/AuctionUpdated.cs
index 89573dc..69a4f09 100644
--- a/src/NotificationService/Contracts/AuctionUpdated.cs
+++ b/src/NotificationService/Contracts/AuctionUpdated.cs
@@ -1,6 +1,6 @@
 namespace Contracts
 {
-    public class AuctionUpdated
+    public sealed class AuctionUpdated
     {
         public string? Id { get; set; }
         public string? Make { get; set; }
@@ -9,4 +9,4 @@ public class AuctionUpdated
         public string? Color { get; set; }
         public int Mileage { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/NotificationService/Contracts/BidPlaced.cs b/src/NotificationService/Contracts/BidPlaced.cs
index c2e6c15..9d37803 100644
--- a/src/NotificationService/Contracts/BidPlaced.cs
+++ b/src/NotificationService/Contracts/BidPlaced.cs
@@ -1,6 +1,6 @@
 namespace Contracts
 {
-    public class BidPlaced
+    public sealed class BidPlaced
     {
         public string? Id { get; set; }
         public string? AuctionId { get; set; }
@@ -9,4 +9,4 @@ public class BidPlaced
         public int Amount { get; set; }
         public string? BidStatus { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/NotificationService/Hubs/NotificationHub.cs b/src/NotificationService/Hubs/NotificationHub.cs
index 6b55c19..5369474 100644
--- a/src/NotificationService/Hubs/NotificationHub.cs
+++ b/src/NotificationService/Hubs/NotificationHub.cs
@@ -1,4 +1,4 @@
 namespace NotificationService.Hubs
 {
-    public class NotificationHub : Hub { }
-}
\ No newline at end of file
+    public sealed class NotificationHub : Hub { }
+}
diff --git a/src/NotificationService/Program.cs b/src/NotificationService/Program.cs
index 9bd751c..46f2ba4 100644
--- a/src/NotificationService/Program.cs
+++ b/src/NotificationService/Program.cs
@@ -30,4 +30,4 @@
 
 app.MapHub<NotificationHub>("/notifications");
 
-app.Run();
\ No newline at end of file
+app.Run();
diff --git a/src/SearchService/Consumers/AuctionCreatedConsumer.cs b/src/SearchService/Consumers/AuctionCreatedConsumer.cs
index 9336fae..7f2786e 100644
--- a/src/SearchService/Consumers/AuctionCreatedConsumer.cs
+++ b/src/SearchService/Consumers/AuctionCreatedConsumer.cs
@@ -6,7 +6,7 @@
 
 namespace SearchService.Consumers
 {
-    public class AuctionCreatedConsumer(IMapper mapper) : IConsumer<AuctionCreated>
+    public sealed class AuctionCreatedConsumer(IMapper mapper) : IConsumer<AuctionCreated>
     {
         public async Task Consume(ConsumeContext<AuctionCreated> context)
         {
@@ -19,4 +19,4 @@ public async Task Consume(ConsumeContext<AuctionCreated> context)
             await item.SaveAsync();
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/SearchService/Consumers/AuctionDeletedConsumer.cs b/src/SearchService/Consumers/AuctionDeletedConsumer.cs
index 1e35e09..ad105c6 100644
--- a/src/SearchService/Consumers/AuctionDeletedConsumer.cs
+++ b/src/SearchService/Consumers/AuctionDeletedConsumer.cs
@@ -6,7 +6,7 @@
 
 namespace SearchService.Consumers
 {
-    public class AuctionDeletedConsumer : IConsumer<AuctionDeleted>
+    public sealed class AuctionDeletedConsumer : IConsumer<AuctionDeleted>
     {
         public async Task Consume(ConsumeContext<AuctionDeleted> context)
         {
@@ -18,4 +18,4 @@ public async Task Consume(ConsumeContext<AuctionDeleted> context)
                 throw new MessageException(typeof(AuctionDeleted), "Problem deleting auction.");
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/SearchService/Consumers/AuctionFinishedConsumer.cs b/src/SearchService/Consumers/AuctionFinishedConsumer.cs
index 81ec6cb..fb14492 100644
--- a/src/SearchService/Consumers/AuctionFinishedConsumer.cs
+++ b/src/SearchService/Consumers/AuctionFinishedConsumer.cs
@@ -5,7 +5,7 @@
 
 namespace SearchService.Consumers
 {
-    public class AuctionFinishedConsumer : IConsumer<AuctionFinished>
+    public sealed class AuctionFinishedConsumer : IConsumer<AuctionFinished>
     {
         public async Task Consume(ConsumeContext<AuctionFinished> context)
         {
@@ -22,4 +22,4 @@ public async Task Consume(ConsumeContext<AuctionFinished> context)
             await auction.SaveAsync();
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/SearchService/Consumers/AuctionUpdatedConsumer.cs b/src/SearchService/Consumers/AuctionUpdatedConsumer.cs
index ff5240c..fd416ab 100644
--- a/src/SearchService/Consumers/AuctionUpdatedConsumer.cs
+++ b/src/SearchService/Consumers/AuctionUpdatedConsumer.cs
@@ -7,7 +7,7 @@
 
 namespace SearchService.Consumers
 {
-    public class AuctionUpdatedConsumer(IMapper mapper) : IConsumer<AuctionUpdated>
+    public sealed class AuctionUpdatedConsumer(IMapper mapper) : IConsumer<AuctionUpdated>
     {
         public async Task Consume(ConsumeContext<AuctionUpdated> context)
         {
@@ -30,4 +30,4 @@ public async Task Consume(ConsumeContext<AuctionUpdated> context)
                 throw new MessageException(typeof(AuctionUpdated), "Problem updating mongodb");
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/SearchService/Consumers/BidPlacedConsumer.cs b/src/SearchService/Consumers/BidPlacedConsumer.cs
index 4f8478a..c8ab14e 100644
--- a/src/SearchService/Consumers/BidPlacedConsumer.cs
+++ b/src/SearchService/Consumers/BidPlacedConsumer.cs
@@ -5,7 +5,7 @@
 
 namespace SearchService.Consumers
 {
-    public class BidPlacedConsumer : IConsumer<BidPlaced>
+    public sealed class BidPlacedConsumer : IConsumer<BidPlaced>
     {
         public async Task Consume(ConsumeContext<BidPlaced> context)
         {
@@ -21,4 +21,4 @@ public async Task Consume(ConsumeContext<BidPlaced> context)
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/SearchService/Contracts/AuctionCreated.cs b/src/SearchService/Contracts/AuctionCreated.cs
index 3b7789c..609b633 100644
--- a/src/SearchService/Contracts/AuctionCreated.cs
+++ b/src/SearchService/Contracts/AuctionCreated.cs
@@ -1,6 +1,6 @@
 namespace Contracts
 {
-    public class AuctionCreated
+    public sealed class AuctionCreated
     {
         public Guid Id { get; set; }
         public int ReservePrice { get; set; }
@@ -19,4 +19,4 @@ public class AuctionCreated
         public int Mileage { get; set; }
         public string ImageUrl { get; set; } = string.Empty;
     }
-}
\ No newline at end of file
+}
diff --git a/src/SearchService/Contracts/AuctionDeleted.cs b/src/SearchService/Contracts/AuctionDeleted.cs
index 6a7166f..9d44170 100644
--- a/src/SearchService/Contracts/AuctionDeleted.cs
+++ b/src/SearchService/Contracts/AuctionDeleted.cs
@@ -1,7 +1,7 @@
 namespace Contracts
 {
-    public class AuctionDeleted
+    public sealed class AuctionDeleted
     {
         public string? Id { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/SearchService/Contracts/AuctionFinished.cs b/src/SearchService/Contracts/AuctionFinished.cs
index efaa03c..5e5c825 100644
--- a/src/SearchService/Contracts/AuctionFinished.cs
+++ b/src/SearchService/Contracts/AuctionFinished.cs
@@ -1,6 +1,6 @@
 namespace SearchService.Contracts
 {
-    public class AuctionFinished
+    public sealed class AuctionFinished
     {
         public bool ItemSold { get; set; }
         public string? AuctionId { get; set; }
@@ -8,4 +8,4 @@ public class AuctionFinished
         public string? Seller { get; set; }
         public int? Amount { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/SearchService/Contracts/AuctionUpdated.cs b/src/SearchService/Contracts/AuctionUpdated.cs
index 89573dc..69a4f09 100644
--- a/src/SearchService/Contracts/AuctionUpdated.cs
+++ b/src/SearchService/Contracts/AuctionUpdated.cs
@@ -1,6 +1,6 @@
 namespace Contracts
 {
-    public class AuctionUpdated
+    public sealed class AuctionUpdated
     {
         public string? Id { get; set; }
         public string? Make { get; set; }
@@ -9,4 +9,4 @@ public class AuctionUpdated
         public string? Color { get; set; }
         public int Mileage { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/SearchService/Contracts/BidPlaced.cs b/src/SearchService/Contracts/BidPlaced.cs
index 3da18d5..af4890a 100644
--- a/src/SearchService/Contracts/BidPlaced.cs
+++ b/src/SearchService/Contracts/BidPlaced.cs
@@ -1,6 +1,6 @@
 namespace SearchService.Contracts
 {
-    public class BidPlaced
+    public sealed class BidPlaced
     {
         public string? Id { get; set; }
         public string? AuctionId { get; set; }
@@ -9,4 +9,4 @@ public class BidPlaced
         public int Amount { get; set; }
         public string? BidStatus { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/SearchService/Controllers/SearchController.cs b/src/SearchService/Controllers/SearchController.cs
index f3f403f..760b6e9 100644
--- a/src/SearchService/Controllers/SearchController.cs
+++ b/src/SearchService/Controllers/SearchController.cs
@@ -7,7 +7,7 @@ namespace SearchService.Controllers
 {
     [ApiController]
     [Route("api/search")]
-    public class SearchController : ControllerBase
+    public sealed class SearchController : ControllerBase
     {
         [HttpGet]
         public async Task<ActionResult<List<Item>>> SearchItems([FromQuery] SearchParams searchParams)
@@ -54,4 +54,4 @@ public async Task<ActionResult<List<Item>>> SearchItems([FromQuery] SearchParams
             });
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/SearchService/Data/DbInitializer.cs b/src/SearchService/Data/DbInitializer.cs
index f4b6e2c..232fe2c 100644
--- a/src/SearchService/Data/DbInitializer.cs
+++ b/src/SearchService/Data/DbInitializer.cs
@@ -5,7 +5,7 @@
 
 namespace SearchService.Data
 {
-    public class DbInitializer
+    public sealed class DbInitializer
     {
         public static async Task InitDb(WebApplication app)
         {
@@ -31,4 +31,4 @@ await DB.Index<Item>()
             if (items.Count > 0) await DB.SaveAsync(items);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/SearchService/Models/Item.cs b/src/SearchService/Models/Item.cs
index 61fa228..4d24e36 100644
--- a/src/SearchService/Models/Item.cs
+++ b/src/SearchService/Models/Item.cs
@@ -2,7 +2,7 @@
 
 namespace SearchService.Models
 {
-    public class Item : Entity
+    public sealed class Item : Entity
     {
         public int ReservePrice { get; set; }
         public string? Seller { get; set; }
@@ -20,4 +20,4 @@ public class Item : Entity
         public int Mileage { get; set; }
         public string ImageUrl { get; set; } = string.Empty;
     }
-}
\ No newline at end of file
+}
diff --git a/src/SearchService/Program.cs b/src/SearchService/Program.cs
index 42c3f52..c337eb5 100644
--- a/src/SearchService/Program.cs
+++ b/src/SearchService/Program.cs
@@ -63,4 +63,4 @@ static IAsyncPolicy<HttpResponseMessage> GetPolicy() =>
         .OrResult(msg => msg.StatusCode == HttpStatusCode.NotFound)
         .WaitAndRetryForeverAsync(_ => TimeSpan.FromSeconds(3));
 
-public partial class Program {}
+public sealed partial class Program {}
diff --git a/src/SearchService/RequestHelpers/MappingProfiles.cs b/src/SearchService/RequestHelpers/MappingProfiles.cs
index e14b096..5940696 100644
--- a/src/SearchService/RequestHelpers/MappingProfiles.cs
+++ b/src/SearchService/RequestHelpers/MappingProfiles.cs
@@ -4,11 +4,11 @@
 
 namespace SearchService.RequestHelpers
 {
-    public class MappingProfiles : Profile
+    public sealed class MappingProfiles : Profile
     {
         public MappingProfiles()
         {
             CreateMap<AuctionCreated, Item>();
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/SearchService/RequestHelpers/SearchParams.cs b/src/SearchService/RequestHelpers/SearchParams.cs
index 5be972c..fbe4465 100644
--- a/src/SearchService/RequestHelpers/SearchParams.cs
+++ b/src/SearchService/RequestHelpers/SearchParams.cs
@@ -1,6 +1,6 @@
 namespace SearchService.RequestHelpers
 {
-    public class SearchParams
+    public sealed class SearchParams
     {
         public string? SearchTerm { get; set; }
         public int PageNumber { get; set; } = 1;
@@ -10,4 +10,4 @@ public class SearchParams
         public string? OrderBy { get; set; }
         public string? FilterBy { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/SearchService/Services/AuctionServiceHttpClient.cs b/src/SearchService/Services/AuctionServiceHttpClient.cs
index 12bf09f..63f3370 100644
--- a/src/SearchService/Services/AuctionServiceHttpClient.cs
+++ b/src/SearchService/Services/AuctionServiceHttpClient.cs
@@ -3,7 +3,7 @@
 
 namespace SearchService.Services
 {
-    public class AuctionServiceHttpClient(HttpClient httpClient, IConfiguration config)
+    public sealed class AuctionServiceHttpClient(HttpClient httpClient, IConfiguration config)
     {
         public async Task<List<Item>> GetItemsForSearchDb()
         {
@@ -19,4 +19,4 @@ public async Task<List<Item>> GetItemsForSearchDb()
             return response!;
         }
     }
-}
\ No newline at end of file
+}
diff --git a/tests/AuctionService.IntegrationTests/AuctionBusTests.cs b/tests/AuctionService.IntegrationTests/AuctionBusTests.cs
index 9c6b91e..87c92ed 100644
--- a/tests/AuctionService.IntegrationTests/AuctionBusTests.cs
+++ b/tests/AuctionService.IntegrationTests/AuctionBusTests.cs
@@ -1,7 +1,7 @@
 namespace AuctionService.IntegrationTests
 {
     [Collection("SharedFixture")]
-    public class AuctionBusTests : IAsyncLifetime
+    public sealed class AuctionBusTests : IAsyncLifetime
     {
         private readonly CustomWebAppFactory _factory;
         private readonly HttpClient _httpClient;
@@ -51,4 +51,4 @@ private static CreateAuctionDto GetAuctionForCreate() =>
                 Color = "Red"
             };
     }
-}
\ No newline at end of file
+}
diff --git a/tests/AuctionService.IntegrationTests/AuctionControllerTests.cs b/tests/AuctionService.IntegrationTests/AuctionControllerTests.cs
index 48b223e..c455c04 100644
--- a/tests/AuctionService.IntegrationTests/AuctionControllerTests.cs
+++ b/tests/AuctionService.IntegrationTests/AuctionControllerTests.cs
@@ -1,7 +1,7 @@
 namespace AuctionService.IntegrationTests
 {
     [Collection("SharedFixture")]
-    public class AuctionControllerTests : IAsyncLifetime
+    public sealed class AuctionControllerTests : IAsyncLifetime
     {
         private readonly CustomWebAppFactory _factory;
         private readonly HttpClient _httpClient;
@@ -168,4 +168,4 @@ private static CreateAuctionDto GetAuctionForCreate() =>
                 Color = "Red"
             };
     }
-}
\ No newline at end of file
+}
diff --git a/tests/AuctionService.IntegrationTests/Fixtures/CustomWebAppFactory.cs b/tests/AuctionService.IntegrationTests/Fixtures/CustomWebAppFactory.cs
index 763cbd5..699c1d2 100644
--- a/tests/AuctionService.IntegrationTests/Fixtures/CustomWebAppFactory.cs
+++ b/tests/AuctionService.IntegrationTests/Fixtures/CustomWebAppFactory.cs
@@ -3,7 +3,7 @@ namespace AuctionService.IntegrationTests.Fixtures
     /// <summary>
     /// Represents a custom web application factory used for integration testing.
     /// </summary>
-    public class CustomWebAppFactory : WebApplicationFactory<Program>, IAsyncLifetime
+    public sealed class CustomWebAppFactory : WebApplicationFactory<Program>, IAsyncLifetime
     {
         /// <summary>
         /// Represents a PostgreSqlContainer used for integration testing.
@@ -16,7 +16,7 @@ public async Task InitializeAsync() =>
         async Task IAsyncLifetime.DisposeAsync() =>
             await _postgresSqlContainer.DisposeAsync().AsTask();
 
-        protected override void ConfigureWebHost(IWebHostBuilder builder)
+        protected sealed override void ConfigureWebHost(IWebHostBuilder builder)
         {
             builder.ConfigureTestServices(services =>
             {
@@ -39,4 +39,4 @@ protected override void ConfigureWebHost(IWebHostBuilder builder)
             });
         }
     }
-}
\ No newline at end of file
+}
diff --git a/tests/AuctionService.IntegrationTests/Fixtures/SharedFixture.cs b/tests/AuctionService.IntegrationTests/Fixtures/SharedFixture.cs
index eebf3d7..ae944c0 100644
--- a/tests/AuctionService.IntegrationTests/Fixtures/SharedFixture.cs
+++ b/tests/AuctionService.IntegrationTests/Fixtures/SharedFixture.cs
@@ -1,8 +1,8 @@
 namespace AuctionService.IntegrationTests.Fixtures
 {
     [CollectionDefinition("SharedFixture")]
-    public class SharedFixture : ICollectionFixture<CustomWebAppFactory>
+    public sealed class SharedFixture : ICollectionFixture<CustomWebAppFactory>
     {
         
     }
-}
\ No newline at end of file
+}
diff --git a/tests/AuctionService.IntegrationTests/GlobalUsings.cs b/tests/AuctionService.IntegrationTests/GlobalUsings.cs
index c17b231..ec804da 100644
--- a/tests/AuctionService.IntegrationTests/GlobalUsings.cs
+++ b/tests/AuctionService.IntegrationTests/GlobalUsings.cs
@@ -9,9 +9,11 @@
 global using Testcontainers.PostgreSql;
 global using AuctionService.IntegrationTests.Fixtures;
 global using AuctionService.IntegrationTests.Utils;
-global using System.Net.Http.Json;
+global using AuctionService.Entities;
 global using AuctionService.Dtos;
 global using WebMotions.Fake.Authentication.JwtBearer;
+global using System.Security.Claims;
+global using System.Net.Http.Json;
 global using System.Net;
 global using Contracts;
 global using MassTransit.Testing;
\ No newline at end of file
diff --git a/tests/AuctionService.IntegrationTests/Utils/AuthHelper.cs b/tests/AuctionService.IntegrationTests/Utils/AuthHelper.cs
index 9b69a0e..4919766 100644
--- a/tests/AuctionService.IntegrationTests/Utils/AuthHelper.cs
+++ b/tests/AuctionService.IntegrationTests/Utils/AuthHelper.cs
@@ -1,13 +1,11 @@
-using System.Security.Claims;
-
 namespace AuctionService.IntegrationTests.Utils
 {
-    public class AuthHelper
+    public sealed class AuthHelper
     {
         public static Dictionary<string, object> GetBearerForUser(string username) =>
             new()
             {
-                {ClaimTypes.Name, username}
+                { ClaimTypes.Name, username }
             };
     }
-}
\ No newline at end of file
+}
diff --git a/tests/AuctionService.IntegrationTests/Utils/DataHelper.cs b/tests/AuctionService.IntegrationTests/Utils/DataHelper.cs
index de1263e..86310f7 100644
--- a/tests/AuctionService.IntegrationTests/Utils/DataHelper.cs
+++ b/tests/AuctionService.IntegrationTests/Utils/DataHelper.cs
@@ -1,5 +1,3 @@
-using AuctionService.Entities;
-
 namespace AuctionService.IntegrationTests.Utils
 {
     public static class DataHelper
@@ -20,4 +18,4 @@ public static void ReinitDbForTests(AuctionContext db)
         private static List<Auction> GetAuctionsForTest() =>
             DbInitializer.GetDbAuctions();
     }
-}
\ No newline at end of file
+}
diff --git a/tests/AuctionService.IntegrationTests/Utils/ServiceCollectionExtensions.cs b/tests/AuctionService.IntegrationTests/Utils/ServiceCollectionExtensions.cs
index 553fb72..cd25af5 100644
--- a/tests/AuctionService.IntegrationTests/Utils/ServiceCollectionExtensions.cs
+++ b/tests/AuctionService.IntegrationTests/Utils/ServiceCollectionExtensions.cs
@@ -33,4 +33,4 @@ public static void EnsureCreated<T>(this IServiceCollection services)
             DataHelper.InitDbForTests(db);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/tests/AuctionService.UnitTests/AuctionControllerTests.cs b/tests/AuctionService.UnitTests/AuctionControllerTests.cs
index a3ec640..b90da1c 100644
--- a/tests/AuctionService.UnitTests/AuctionControllerTests.cs
+++ b/tests/AuctionService.UnitTests/AuctionControllerTests.cs
@@ -1,6 +1,6 @@
 namespace AuctionService.UnitTests
 {
-    public class AuctionControllerTests
+    public sealed class AuctionControllerTests
     {
         private readonly Mock<IAuctionRepository> _auctionRepository;
         private readonly Mock<IPublishEndpoint> _publishEndpoint;
@@ -205,4 +205,4 @@ public async Task DeleteAuction_WithInvalidUser_Returns403Forbidden()
             Assert.IsType<ForbidResult>(result);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/tests/AuctionService.UnitTests/AuctionEntityTests.cs b/tests/AuctionService.UnitTests/AuctionEntityTests.cs
index 08392a2..1afce48 100644
--- a/tests/AuctionService.UnitTests/AuctionEntityTests.cs
+++ b/tests/AuctionService.UnitTests/AuctionEntityTests.cs
@@ -1,6 +1,6 @@
 namespace AuctionService.UnitTests;
 
-public class AuctionEntityTests
+public sealed class AuctionEntityTests
 {
     [Fact]
     public void HasReservePrice_ReservePriceGtZero_True()
@@ -35,4 +35,4 @@ public void HasReservePrice_ReservePriceIsZero_False()
         // Assert
         Assert.False(result);
     }
-}
\ No newline at end of file
+}
diff --git a/tests/AuctionService.UnitTests/Utils/AuthHelper.cs b/tests/AuctionService.UnitTests/Utils/AuthHelper.cs
index 2b661c6..bf37bfa 100644
--- a/tests/AuctionService.UnitTests/Utils/AuthHelper.cs
+++ b/tests/AuctionService.UnitTests/Utils/AuthHelper.cs
@@ -2,7 +2,7 @@
 
 namespace AuctionService.UnitTests.Utils
 {
-    public class AuthHelper
+    public sealed class AuthHelper
     {
         public static ClaimsPrincipal GetClaimsPrincipal()
         {
@@ -17,4 +17,4 @@ public static ClaimsPrincipal GetClaimsPrincipal()
             return claimsPrincipal;
         }
     }
-}
\ No newline at end of file
+}
diff --git a/tests/SearchService.IntegrationTests/ConsumerTests.cs b/tests/SearchService.IntegrationTests/ConsumerTests.cs
index fa4a8f5..913d7ce 100644
--- a/tests/SearchService.IntegrationTests/ConsumerTests.cs
+++ b/tests/SearchService.IntegrationTests/ConsumerTests.cs
@@ -2,7 +2,7 @@
 
 namespace SearchService.IntegrationTests
 {
-    public class ConsumerTests(CustomWebAppFactory factory) : IClassFixture<CustomWebAppFactory>
+    public sealed class ConsumerTests(CustomWebAppFactory factory) : IClassFixture<CustomWebAppFactory>
     {
         private readonly ITestHarness _testHarness = factory.Services.GetTestHarness();
         private readonly Fixture _fixture = new();
@@ -24,4 +24,4 @@ public async Task AuctionCreated_ShouldCreateItemInDb()
             Assert.Equal(auction.Make, item.Make);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/tests/SearchService.IntegrationTests/CustomWebAppFactory.cs b/tests/SearchService.IntegrationTests/CustomWebAppFactory.cs
index de1a355..5a83330 100644
--- a/tests/SearchService.IntegrationTests/CustomWebAppFactory.cs
+++ b/tests/SearchService.IntegrationTests/CustomWebAppFactory.cs
@@ -1,6 +1,6 @@
 namespace SearchService.IntegrationTests
 {
-    public class CustomWebAppFactory : WebApplicationFactory<Program>
+    public sealed class CustomWebAppFactory : WebApplicationFactory<Program>
     {
         private readonly MongoDbRunner _runner;
 
@@ -16,7 +16,7 @@ public CustomWebAppFactory()
                 .CreateAsync();
         }
 
-        protected override void ConfigureWebHost(IWebHostBuilder builder)
+        protected sealed override void ConfigureWebHost(IWebHostBuilder builder)
         {
             builder.UseEnvironment("Testing");
             builder.ConfigureTestServices(services => 
@@ -25,7 +25,7 @@ protected override void ConfigureWebHost(IWebHostBuilder builder)
             });
         }
 
-        protected override void Dispose(bool disposing)
+        protected sealed override void Dispose(bool disposing)
         {
             _runner.Dispose();
         }