What is a cold start?
The extra latency when a serverless platform has no ready execution environment for your function and must create one: allocate an isolated sandbox, fetch your code, start the runtime and run your initialization code. Later invocations on the same warm environment skip those steps and are much faster.
Answered in
Serverless Cold Starts Explained: MicroVMs, Snapshots and What You Can ControlWhy a function's first call is slow, how microVMs and snapshot restore cut it, and the code and config choices that shrink cold starts on your side.
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