diff --git a/README.md b/README.md
index 7316cbd..9e51187 100644
--- a/README.md
+++ b/README.md
@@ -111,6 +111,7 @@ module "transformer_kinesis" {
 | Name | Description | Type | Default | Required |
 |------|-------------|------|---------|:--------:|
 | <a name="input_name"></a> [name](#input\_name) | A name which will be pre-pended to the resources created | `string` | n/a | yes |
+| <a name="input_app_version"></a> [app\_version](#input\_app\_version) | Version of transformer-kinesis | `string` | "5.8.0" | no |
 | <a name="input_s3_bucket_name"></a> [s3\_bucket\_name](#input\_s3\_bucket\_name) | The name of the S3 bucket events will be loaded into | `string` | n/a | yes |
 | <a name="input_s3_bucket_object_prefix"></a> [s3\_bucket\_object\_prefix](#input\_s3\_bucket\_object\_prefix) | An optional prefix under which Snowplow data will be saved | `string` | n/a | yes |
 | <a name="input_ssh_key_name"></a> [ssh\_key\_name](#input\_ssh\_key\_name) | The name of the SSH key-pair to attach to all EC2 nodes deployed | `string` | n/a | yes |
@@ -145,6 +146,7 @@ module "transformer_kinesis" {
 | <a name="input_transformer_compression"></a> [transformer\_compression](#input\_transformer\_compression) | Transformer output compression, GZIP or NONE | `string` | `"GZIP"` | no |
 | <a name="input_user_provided_id"></a> [user\_provided\_id](#input\_user\_provided\_id) | An optional unique identifier to identify the telemetry events emitted by this stack | `string` | `""` | no |
 | <a name="input_widerow_file_format"></a> [widerow\_file\_format](#input\_widerow\_file\_format) | The output file\_format from the widerow transformation\_type selected (json or parquet) | `string` | `"json"` | no |
+| <a name="input_config_override_b64"></a> [config\_override\_b64](#input\_config\_override\_b64) | App config uploaded as a base64 encoded blob. This variable facilitates dev flow, if config is incorrect this can break the deployment. | `string` | `""` | no |
 
 ## Outputs
 
diff --git a/main.tf b/main.tf
index efe524b..34e64e3 100644
--- a/main.tf
+++ b/main.tf
@@ -3,7 +3,7 @@ locals {
   module_version = "0.3.4"
 
   app_name    = "transformer-kinesis"
-  app_version = "5.6.0"
+  app_version = var.app_version
 
   local_tags = {
     Name           = var.name
@@ -365,7 +365,7 @@ locals {
   })
 
   user_data = templatefile("${path.module}/templates/user-data.sh.tmpl", {
-    config_b64        = base64encode(local.config)
+    config_b64        = var.config_override_b64 == "" ? base64encode(local.config) : var.config_override_b64
     iglu_resolver_b64 = base64encode(local.iglu_resolver)
     version           = local.app_version
 
diff --git a/variables.tf b/variables.tf
index 3eba6d6..c191e7d 100644
--- a/variables.tf
+++ b/variables.tf
@@ -3,6 +3,18 @@ variable "name" {
   type        = string
 }
 
+variable "app_version" {
+  description = "Version of transformer kinesis"
+  type        = string
+  default     = "5.8.0"
+}
+
+variable "config_override_b64" {
+  description = "App config uploaded as a base64 encoded blob. This variable facilitates dev flow, if config is incorrect this can break the deployment."
+  type        = string
+  default     = ""
+}
+
 variable "vpc_id" {
   description = "The VPC to deploy Transformer within"
   type        = string