Saying that local dev and Lambda are different is a strawman. How is that harder than developing on a Mac or Windows (or even Linux) and then testing on a diffe

Saying that local dev and Lambda are different is a strawman. How is that harder than developing on a Mac or Windows (or even Linux) and then testing on a different OS and config via CI/CD? You shouldn't be testing "on your machine" - that's the oldest excuse in the book! You should build your function in a container based on AWS Linux, just the same as you should for a Lambda deploy. That guarantees you the same versions of software, packages, libraries, etc. It makes it possible for me to develop Lambda functions on a Mac and test binary-for-binary to the deployed version. "Nothing you mentioned has anything to do with the ability to test a Lambda" is not ad-hominem, it's a statement of fact.