AWS Lambda cold start optimization strategies

Lambda functions have high first-invocation latency. Users experience 1-5 second delays.

Reduce cold starts: (1) Minimize package size with bundling. (2) Use provisioned concurrency for critical paths. (3) Keep warm with scheduled pings. (4) Avoid VPC unless necessary. (5) Node.js/Python start faster than Java. (6) Use arm64 (Graviton). (7) Lazy-initialize heavy dependencies.

Cold starts happen when Lambda provisions a new environment: download code, start runtime, initialize handler. Larger packages and VPC ENI allocation add time.