diff --git a/src/core/etl/src/Flow/ETL/DSL/functions.php b/src/core/etl/src/Flow/ETL/DSL/functions.php
index 60ae72b11..375db83ac 100644
--- a/src/core/etl/src/Flow/ETL/DSL/functions.php
+++ b/src/core/etl/src/Flow/ETL/DSL/functions.php
@@ -102,6 +102,11 @@ function array_sort(Expression $expression, string $function = null, int $flags
     return new Expression\ArraySort($expression, $function ? Sort::fromString($function) : Sort::sort, $flags, $recursive);
 }
 
+function array_reverse(Expression $expression, bool $preserveKeys = false) : Expression
+{
+    return new Expression\ArrayReverse($expression, $preserveKeys);
+}
+
 function now(\DateTimeZone $time_zone = new \DateTimeZone('UTC')) : Expression
 {
     return new Expression\Now($time_zone);
diff --git a/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayExistsTest.php b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayExistsTest.php
new file mode 100644
index 000000000..1ac5da572
--- /dev/null
+++ b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayExistsTest.php
@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Tests\Integration\Row\Reference\Expression;
+
+use function Flow\ETL\DSL\array_exists;
+use function Flow\ETL\DSL\ref;
+use Flow\ETL\DSL\From;
+use Flow\ETL\DSL\To;
+use Flow\ETL\Flow;
+use Flow\ETL\Memory\ArrayMemory;
+use PHPUnit\Framework\TestCase;
+
+final class ArrayExistsTest extends TestCase
+{
+    public function test_array_exists() : void
+    {
+        (new Flow())
+            ->read(
+                From::array(
+                    [
+                        ['id' => 1, 'array' => ['a' => 1, 'b' => 2, 'c' => 3]],
+                        ['id' => 2],
+                    ]
+                )
+            )
+            ->withEntry('row', ref('row')->unpack())
+            ->renameAll('row.', '')
+            ->withEntry('has_array', array_exists(ref('array'), 'a'))
+            ->drop('row', 'array')
+            ->write(To::memory($memory = new ArrayMemory()))
+            ->run();
+
+        $this->assertSame(
+            [
+                ['id' => 1, 'has_array' => true],
+                ['id' => 2, 'has_array' => false],
+            ],
+            $memory->data
+        );
+    }
+}
diff --git a/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayGetCollectionTest.php b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayGetCollectionTest.php
new file mode 100644
index 000000000..1129f2a4c
--- /dev/null
+++ b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayGetCollectionTest.php
@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Tests\Integration\Row\Reference\Expression;
+
+use function Flow\ETL\DSL\array_get_collection;
+use function Flow\ETL\DSL\ref;
+use Flow\ETL\DSL\From;
+use Flow\ETL\DSL\To;
+use Flow\ETL\Flow;
+use Flow\ETL\Memory\ArrayMemory;
+use PHPUnit\Framework\TestCase;
+
+final class ArrayGetCollectionTest extends TestCase
+{
+    public function test_array_get_collection() : void
+    {
+        (new Flow())
+            ->read(
+                From::array(
+                    [
+                        ['id' => 1, 'array' => [
+                            ['a' => 1, 'b' => 2, 'c' => 3],
+                            ['a' => 1, 'b' => 2, 'c' => 3],
+                            ['a' => 1, 'b' => 2, 'c' => 3],
+                        ]],
+                        ['id' => 2],
+                    ]
+                )
+            )
+            ->withEntry('row', ref('row')->unpack())
+            ->renameAll('row.', '')
+            ->withEntry('result', array_get_collection(ref('array'), 'a', 'c'))
+            ->drop('row', 'array')
+            ->write(To::memory($memory = new ArrayMemory()))
+            ->run();
+
+        $this->assertSame(
+            [
+                ['id' => 1, 'result' => [['a' => 1, 'c' => 3], ['a' => 1, 'c' => 3], ['a' => 1, 'c' => 3]]],
+                ['id' => 2, 'result' => null],
+            ],
+            $memory->data
+        );
+    }
+}
diff --git a/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayGetTest.php b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayGetTest.php
new file mode 100644
index 000000000..63a2847c6
--- /dev/null
+++ b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayGetTest.php
@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Tests\Integration\Row\Reference\Expression;
+
+use function Flow\ETL\DSL\array_get;
+use function Flow\ETL\DSL\ref;
+use Flow\ETL\DSL\From;
+use Flow\ETL\DSL\To;
+use Flow\ETL\Flow;
+use Flow\ETL\Memory\ArrayMemory;
+use PHPUnit\Framework\TestCase;
+
+final class ArrayGetTest extends TestCase
+{
+    public function test_array_get() : void
+    {
+        (new Flow())
+            ->read(
+                From::array(
+                    [
+                        ['id' => 1, 'array' => ['a' => 1, 'b' => 2, 'c' => 3]],
+                        ['id' => 2],
+                    ]
+                )
+            )
+            ->withEntry('row', ref('row')->unpack())
+            ->renameAll('row.', '')
+            ->withEntry('result', array_get(ref('array'), 'b'))
+            ->drop('row', 'array')
+            ->write(To::memory($memory = new ArrayMemory()))
+            ->run();
+
+        $this->assertSame(
+            [
+                ['id' => 1, 'result' => 2],
+                ['id' => 2, 'result' => null],
+            ],
+            $memory->data
+        );
+    }
+}
diff --git a/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayKeyRenameTest.php b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayKeyRenameTest.php
new file mode 100644
index 000000000..a4b841f86
--- /dev/null
+++ b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayKeyRenameTest.php
@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Tests\Integration\Row\Reference\Expression;
+
+use function Flow\ETL\DSL\array_key_rename;
+use function Flow\ETL\DSL\ref;
+use Flow\ETL\DSL\From;
+use Flow\ETL\DSL\To;
+use Flow\ETL\Flow;
+use Flow\ETL\Memory\ArrayMemory;
+use PHPUnit\Framework\TestCase;
+
+final class ArrayKeyRenameTest extends TestCase
+{
+    public function test_array_key_rename() : void
+    {
+        (new Flow())
+            ->read(
+                From::array(
+                    [
+                        ['id' => 1, 'array' => ['a' => 1, 'b' => 2, 'c' => 3]],
+                        ['id' => 2],
+                    ]
+                )
+            )
+            ->withEntry('row', ref('row')->unpack())
+            ->renameAll('row.', '')
+            ->withEntry('array', array_key_rename(ref('array'), 'a', 'd'))
+            ->drop('row')
+            ->write(To::memory($memory = new ArrayMemory()))
+            ->run();
+
+        $this->assertSame(
+            [
+                ['id' => 1, 'array' => ['b' => 2, 'c' => 3, 'd' => 1]],
+                ['id' => 2, 'array' => null],
+            ],
+            $memory->data
+        );
+    }
+}
diff --git a/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayKeysStyleConvertTest.php b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayKeysStyleConvertTest.php
new file mode 100644
index 000000000..9789956ca
--- /dev/null
+++ b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayKeysStyleConvertTest.php
@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Tests\Integration\Row\Reference\Expression;
+
+use function Flow\ETL\DSL\array_keys_style_convert;
+use function Flow\ETL\DSL\ref;
+use Flow\ETL\DSL\From;
+use Flow\ETL\DSL\To;
+use Flow\ETL\Flow;
+use Flow\ETL\Memory\ArrayMemory;
+use PHPUnit\Framework\TestCase;
+
+final class ArrayKeysStyleConvertTest extends TestCase
+{
+    public function test_array_keys_style_convert() : void
+    {
+        (new Flow())
+            ->read(
+                From::array(
+                    [
+                        ['id' => 1, 'array' => ['camelCased' => 1, 'snake_cased' => 2, 'space word' => 3]],
+                    ]
+                )
+            )
+            ->withEntry('row', ref('row')->unpack())
+            ->renameAll('row.', '')
+            ->withEntry('array', array_keys_style_convert(ref('array'), 'kebab'))
+            ->drop('row')
+            ->write(To::memory($memory = new ArrayMemory()))
+            ->run();
+
+        $this->assertSame(
+            [
+                ['id' => 1, 'array' => ['camel-cased' => 1, 'snake-cased' => 2, 'space-word' => 3]],
+            ],
+            $memory->data
+        );
+    }
+}
diff --git a/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayMergeCollectionTest.php b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayMergeCollectionTest.php
new file mode 100644
index 000000000..170a9eb95
--- /dev/null
+++ b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayMergeCollectionTest.php
@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Tests\Integration\Row\Reference\Expression;
+
+use function Flow\ETL\DSL\array_merge_collection;
+use function Flow\ETL\DSL\ref;
+use Flow\ETL\DSL\From;
+use Flow\ETL\DSL\To;
+use Flow\ETL\Flow;
+use Flow\ETL\Memory\ArrayMemory;
+use PHPUnit\Framework\TestCase;
+
+final class ArrayMergeCollectionTest extends TestCase
+{
+    public function test_array_merge_collection() : void
+    {
+        (new Flow())
+            ->read(
+                From::array(
+                    [
+                        ['id' => 1, 'array' => [
+                            ['a' => 1],
+                            ['b' => 2],
+                            ['c' => 3],
+                        ]],
+                        ['id' => 2],
+                    ]
+                )
+            )
+            ->withEntry('row', ref('row')->unpack())
+            ->renameAll('row.', '')
+            ->withEntry('result', array_merge_collection(ref('array')))
+            ->drop('row', 'array')
+            ->write(To::memory($memory = new ArrayMemory()))
+            ->run();
+
+        $this->assertSame(
+            [
+                ['id' => 1, 'result' => ['a' => 1, 'b' => 2, 'c' => 3]],
+                ['id' => 2, 'result' => null],
+            ],
+            $memory->data
+        );
+    }
+}
diff --git a/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayMergeTest.php b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayMergeTest.php
new file mode 100644
index 000000000..6ee120055
--- /dev/null
+++ b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayMergeTest.php
@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Tests\Integration\Row\Reference\Expression;
+
+use function Flow\ETL\DSL\array_merge;
+use function Flow\ETL\DSL\ref;
+use Flow\ETL\DSL\From;
+use Flow\ETL\DSL\To;
+use Flow\ETL\Flow;
+use Flow\ETL\Memory\ArrayMemory;
+use PHPUnit\Framework\TestCase;
+
+final class ArrayMergeTest extends TestCase
+{
+    public function test_array_merge() : void
+    {
+        (new Flow())
+            ->read(
+                From::array(
+                    [
+                        ['id' => 1, 'first' => ['a' => 1, 'b' => 2], 'second' => ['c' => 3]],
+                        ['id' => 2],
+                    ]
+                )
+            )
+            ->withEntry('row', ref('row')->unpack())
+            ->renameAll('row.', '')
+            ->withEntry('array', array_merge(ref('first'), ref('second')))
+            ->drop('row', 'first', 'second')
+            ->write(To::memory($memory = new ArrayMemory()))
+            ->run();
+
+        $this->assertSame(
+            [
+                ['id' => 1, 'array' => ['a' => 1, 'b' => 2, 'c' => 3]],
+                ['id' => 2, 'array' => null],
+            ],
+            $memory->data
+        );
+    }
+}
diff --git a/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayReverseTest.php b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayReverseTest.php
new file mode 100644
index 000000000..2f9afb6d8
--- /dev/null
+++ b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayReverseTest.php
@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Tests\Integration\Row\Reference\Expression;
+
+use function Flow\ETL\DSL\ref;
+use Flow\ETL\DSL\From;
+use Flow\ETL\DSL\To;
+use Flow\ETL\Flow;
+use Flow\ETL\Memory\ArrayMemory;
+use PHPUnit\Framework\TestCase;
+
+final class ArrayReverseTest extends TestCase
+{
+    public function test_array_reverse() : void
+    {
+        (new Flow())
+            ->read(
+                From::array(
+                    [
+                        ['id' => 1, 'array' => ['a' => 1, 'b' => 2, 'c' => 3]],
+                        ['id' => 2],
+                    ]
+                )
+            )
+            ->withEntry('row', ref('row')->unpack())
+            ->renameAll('row.', '')
+            ->drop('row')
+            ->withEntry('array', ref('array')->arrayReverse())
+            ->write(To::memory($memory = new ArrayMemory()))
+            ->run();
+
+        $this->assertSame(
+            [
+                ['id' => 1, 'array' => ['c' => 3, 'b' => 2, 'a' => 1]],
+                ['id' => 2, 'array' => null],
+            ],
+            $memory->data
+        );
+    }
+}
diff --git a/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArraySortTest.php b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArraySortTest.php
new file mode 100644
index 000000000..fa22de87c
--- /dev/null
+++ b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArraySortTest.php
@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Tests\Integration\Row\Reference\Expression;
+
+use function Flow\ETL\DSL\ref;
+use Flow\ETL\DSL\From;
+use Flow\ETL\DSL\To;
+use Flow\ETL\Flow;
+use Flow\ETL\Memory\ArrayMemory;
+use PHPUnit\Framework\TestCase;
+
+final class ArraySortTest extends TestCase
+{
+    public function test_array_sort() : void
+    {
+        (new Flow())
+            ->read(
+                From::array(
+                    [
+                        ['id' => 1, 'array' => ['a' => 1, 'c' => 3, 'b' => 2]],
+                        ['id' => 2],
+                    ]
+                )
+            )
+            ->withEntry('row', ref('row')->unpack())
+            ->renameAll('row.', '')
+            ->drop('row')
+            ->withEntry('array', ref('array')->arraySort('ksort'))
+            ->write(To::memory($memory = new ArrayMemory()))
+            ->run();
+
+        $this->assertSame(
+            [
+                ['id' => 1, 'array' => ['a' => 1, 'b' => 2, 'c' => 3]],
+                ['id' => 2, 'array' => null],
+            ],
+            $memory->data
+        );
+    }
+}
diff --git a/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayUnpackTest.php b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayUnpackTest.php
new file mode 100644
index 000000000..06b40ce0b
--- /dev/null
+++ b/src/core/etl/tests/Flow/ETL/Tests/Integration/Row/Reference/Expression/ArrayUnpackTest.php
@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Tests\Integration\Row\Reference\Expression;
+
+use function Flow\ETL\DSL\ref;
+use Flow\ETL\DSL\From;
+use Flow\ETL\DSL\To;
+use Flow\ETL\Flow;
+use Flow\ETL\Memory\ArrayMemory;
+use PHPUnit\Framework\TestCase;
+
+final class ArrayUnpackTest extends TestCase
+{
+    public function test_array_unpack() : void
+    {
+        (new Flow())
+            ->read(
+                From::array(
+                    [
+                        ['id' => 1, 'array' => ['a' => 1, 'b' => 2, 'c' => 3]],
+                        ['id' => 2],
+                    ]
+                )
+            )
+            ->withEntry('row', ref('row')->unpack())
+            ->renameAll('row.', '')
+            ->drop('row')
+            ->write(To::memory($memory = new ArrayMemory()))
+            ->run();
+
+        $this->assertSame(
+            [
+                ['id' => 1, 'array' => ['a' => 1, 'b' => 2, 'c' => 3]],
+                ['id' => 2],
+            ],
+            $memory->data
+        );
+    }
+}