Lambda SnapStart snapshots the fully initialized JVM after the init phase and restores it instantly on cold starts — dropping Java Lambda cold starts from 8 seconds to under 100ms without changing a line of application code.

Lambda Layers separate your dependencies from your function code. Shared libraries across functions, smaller deployment packages, faster cold starts, and centralized dependency management — all from a feature most developers underuse.

CloudWatch Insights is the most underused AWS debugging tool. These 10 production-tested queries find Lambda cold starts, latency spikes, memory leaks, and error patterns in minutes.

Presigned URLs seem simple but hide serious security traps: excessively long expiry, no bucket policy enforcement, credential exposure in logs, and SSRF vulnerability patterns.

DynamoDB single-table design feels counterintuitive at first. One table for everything, no joins, access patterns defined upfront. Once you understand it, you never go back.

Cold starts are killing your Lambda API. Here are 6 techniques that drop cold start latency from 2s to under 200ms — most of them completely free.