cold-start-budget-reference

Overview

Per aws.amazon.com/blogs/compute on cold starts, Lambda's cold start has three phases:

1. Init - download deployment package, unzip, bootstrap the runtime (Node/Python/Java/etc.).
2. Init code - execute module-level imports + global setup.
3. Invoke - the actual handler call.

Phases 1 + 2 are the "cold" part. Phase 3 is what runs every invocation (cold or warm).

When to use