[phillu]

I had great success with unit testing the lambda code and mocking external/aws services.

For serious software you want a proper local/unit test setup anyway. Using this in your dev cycles is just the natural next step. Instead of waiting for the cdk/cfn deploy to finish, which really is way too slow, you just execute 'jest' or whatever test framework you have.

Sure, figuring out how to mock everything takes some upfront time, but it pays off in the long run.