diff --git a/serverless.yml b/serverless.yml
index a8e64107..c27c0658 100644
--- a/serverless.yml
+++ b/serverless.yml
@@ -1,9 +1,18 @@
 service: retrofit-platform
 
+frameworkVersion: '3'
+
 provider:
   name: aws
   region: eu-west-2
   architecture: x86_64
+
+  # REQUIRED for TRUE image Lambdas in Serverless v3
+  ecr:
+    images:
+      modelEngineImage:
+        uri: ${env:ECR_URI}:${env:GITHUB_SHA}
+
   environment:
     API_KEY: ${env:API_KEY}
     ENVIRONMENT: ${env:ENVIRONMENT}
@@ -18,8 +27,6 @@ provider:
     DB_USERNAME: ${env:DB_USERNAME}
     DB_PASSWORD: ${env:DB_PASSWORD}
     DB_PORT: ${env:DB_PORT}
-    ECR_URI: ${env:ECR_URI}
-    GITHUB_SHA: ${env:GITHUB_SHA}
     SAP_PREDICTIONS_BUCKET: ${env:SAP_PREDICTIONS_BUCKET}
     CARBON_PREDICTIONS_BUCKET: ${env:CARBON_PREDICTIONS_BUCKET}
     HEAT_PREDICTIONS_BUCKET: ${env:HEAT_PREDICTIONS_BUCKET}
@@ -35,11 +42,11 @@ plugins:
   - serverless-domain-manager
 
 custom:
-  custom:
-    pythonRequirements:
-      fileName: backend/app/requirements/requirements.txt
-      dockerizePip: true
-      pythonBin: python3.11
+  pythonRequirements:
+    fileName: backend/app/requirements/requirements.txt
+    dockerizePip: true
+    pythonBin: python3.11
+
   customDomain:
     domainName: api.${self:provider.environment.DOMAIN_NAME}
     createRoute53Record: true
@@ -47,7 +54,9 @@ custom:
 
 functions:
 
-  # ZIP-based Lambda (FastAPI)
+  # ─────────────────────────────────────────────
+  # ZIP-BASED FASTAPI LAMBDA
+  # ─────────────────────────────────────────────
   fastapi-backend:
     runtime: python3.11
     handler: backend.app.main.handler
@@ -59,10 +68,12 @@ functions:
           path: /{proxy+}
           method: ANY
 
-  # TRUE container-image Lambda (4 GB+ supported)
+  # ─────────────────────────────────────────────
+  # TRUE CONTAINER-IMAGE LAMBDA (4GB+ SUPPORTED)
+  # ─────────────────────────────────────────────
   model-engine-lambda:
     image:
-      uri: ${env:ECR_URI}:${env:GITHUB_SHA}
+      name: modelEngineImage
     timeout: 900
     memorySize: 4096
     role: EngineLambdaRole