What you're describing is the cold start[1] request lifecycle for Lambda functions. But if a successive request comes soon thereafter, there's a faster warm sta

What you're describing is the cold start[1] request lifecycle for Lambda functions. But if a successive request comes soon thereafter, there's a faster warm start path, which is significantly quicker (~ <100ms). There's also a way to "provision"[2] resources to ensure that the function always stays warm, but that adds to the fixed cost, which is otherwise, near zero, if there are no requests. [1]: https://aws.amazon.com/blogs/compute/operating-lambda-performance-optimization-part-1/ https://aws.amazon.com/blogs/compute/operating-lambda-perfor... [2]: https://aws.amazon.com/blogs/aws/new-provisioned-concurrency-for-lambda-functions/ https://aws.amazon.com/blogs/aws/new-provisioned-concurrency...