diff --git a/.github/workflows/deploy_terraform.yml b/.github/workflows/deploy_terraform.yml
index 923fc0a9..8ba473ca 100644
--- a/.github/workflows/deploy_terraform.yml
+++ b/.github/workflows/deploy_terraform.yml
@@ -169,7 +169,7 @@ jobs:
     uses: ./.github/workflows/_build_image.yml
     with:
       ecr_repo: postcode_splitter-${{ needs.determine_stage.outputs.stage }}
-      dockerfile_path: backend/postcode_splitter/handler/Dockerfile
+      dockerfile_path: applications/postcode_splitter/Dockerfile
       build_context: .
       build_args: |
         DEV_DB_HOST=$DEV_DB_HOST
diff --git a/.github/workflows/lambda_smoke_tests.yml b/.github/workflows/lambda_smoke_tests.yml
index 5ff5420a..b562f91e 100644
--- a/.github/workflows/lambda_smoke_tests.yml
+++ b/.github/workflows/lambda_smoke_tests.yml
@@ -36,6 +36,13 @@ jobs:
       build_context: .
       service_name: postcode-splitter
 
+  postcode_splitter_ddd_smoke_test:
+    uses: ./.github/workflows/_smoke_test_lambda.yml
+    with:
+      dockerfile_path: applications/postcode_splitter/Dockerfile
+      build_context: .
+      service_name: postcode-splitter-ddd
+
   # ============================================================
   # Bulk Address2UPRN Combiner
   # ============================================================
diff --git a/deployment/terraform/lambda/postcodeSplitter/main.tf b/deployment/terraform/lambda/postcodeSplitter/main.tf
index 325f7dc7..721cb2ea 100644
--- a/deployment/terraform/lambda/postcodeSplitter/main.tf
+++ b/deployment/terraform/lambda/postcodeSplitter/main.tf
@@ -38,8 +38,8 @@ module "lambda" {
     {
       STAGE     = var.stage
       LOG_LEVEL = "info"
-      DB_USERNAME = local.db_credentials.db_assessment_model_username
-      DB_PASSWORD = local.db_credentials.db_assessment_model_password
+      POSTGRES_USERNAME = local.db_credentials.db_assessment_model_username
+      POSTGRES_PASSWORD = local.db_credentials.db_assessment_model_password
       ADDRESS2UPRN_QUEUE_URL = data.terraform_remote_state.address2uprn.outputs.address2uprn_queue_url
       S3_BUCKET_NAME = data.terraform_remote_state.shared.outputs.retrofit_sap_data_bucket_name
     },