AWS Amplify Cold Start Prevention Guide
For developers using AWS Amplify's serverless functions.
How do Amplify serverless functions handle cold starts?
AWS Amplify serverless functions are AWS Lambda functions under the hood, so they follow the same cold start behavior. Unused functions get recycled, creating latency spikes.
Can I prevent Amplify function cold starts?
Yes. Unlike pure Lambda, Amplify provides API Gateway endpoints automatically for your functions, making them easier to keep warm.
How does Keep Alive keep Amplify functions warm?
Keep Alive pings your function's API Gateway URL at regular intervals:
- Ensures container remains provisioned
- Works with JS/TS, Python or other Amplify-supported runtimes
- Maintains separate warm instances for each environment (dev/prod)
Setup guide
- Identify your Amplify function's URL pattern:
https://[api-id].execute-api.[region].amazonaws.com/[stage]/[function-name] - Add this URL to Keep Alive
- Set ping interval to 5 minutes (recommended for Lambda)
- Optionally add authentication headers if your endpoint requires them
Best practices for Amplify functions
- Dedicated endpoint: Create lightweight ping endpoints
- Dependency management: Minimize dependencies for faster cold start recovery
- Function combination: Consider bundling critical functions together
- Error handling: Ensure proper error handling in your warmup path
Common Amplify function challenges
Amplify functions have some unique considerations compared to standalone Lambda:
- Authentication: If using Cognito or API keys, your ping may need auth headers
- Environment variables: Environment-specific configs need separate pings
- GraphQL resolvers: Custom resolvers need their own keep-alive strategy
- Multi-environment: Dev/test/prod each need separate ping configurations
Costs and performance impact
Keeping Amplify functions warm has minimal cost impact while significantly improving user experience:
- 5-minute pings = ~8,640 invocations per month (well within free tier)
- Cold start improvement: 500ms-5s → consistent 50-100ms responses
- Better user retention due to snappy initial responses
Amplify vs other platforms
AWS Amplify functions have specific characteristics compared to other platforms:
- Amplify: Built on Lambda with integrated auth → Fully mitigated with Keep Alive
- Pure Lambda: More configuration options but similar cold start behavior → Same mitigation
- Vercel/Netlify: Similar Lambda-based architecture → Similar warming benefits