Add AWS Lambda Bundle Size Optimization Guide and update build scripts for Prisma layer

serverless.yml

@@ -7,9 +7,9 @@ provider:
   versionFunctions: false
   memorySize: 512
   # Apply Prisma layer to all functions
-  # Use the published layer version ARN (works for full deploy and `deploy function`)
+  # Reference the layer defined in this stack using CloudFormation Ref
   layers:
-    - ${cf:${self:service}-${sls:stage}.PrismaLambdaLayerQualifiedArn}
+    - !Ref PrismaLambdaLayer
   apiGateway:
     binaryMediaTypes:
       - '*/*'
@@ -68,14 +68,32 @@ build:
     sourcemap: false
     target: node20
     platform: node
+    # Mark as external so they're not bundled into the JS
     external:
-      # These are provided by the Prisma layer
+      - '@prisma/client'
+      - '@prisma/adapter-pg'
+      - '.prisma/client'
+      - '.prisma'
+      - 'pg'
+      - '@aws-sdk/*'
+      - '@smithy/*'
+      - '@aws-crypto/*'
+    # Exclude prevents npm install of these packages in the zip
+    exclude:
+      - 'aws-sdk'
+      - '@aws-sdk/*'
+      - '@smithy/*'
+      - '@aws-crypto/*'
       - '@prisma/client'
       - '@prisma/adapter-pg'
       - '.prisma'
+      - '.prisma/client'
       - 'pg'
-    exclude:
-      - 'aws-sdk'
+      - 'pg-*'
+      - 'postgres-*'
+      - 'pgpass'
+      - 'split2'
+      - 'xtend'
  
 # Define layers
 layers:
@@ -91,6 +109,8 @@ package:
   individually: true
   patterns:
     - '!node_modules/**'
+    - '!node_modules/@prisma/**'
+    - '!node_modules/.prisma/**'
     - '!**/*.test.js'
     - '!**/*.spec.js'
     - '!**/test/**'