Ask HN: What not to do with AWS Lambda?

I am working on my thesis and I need advice from the AWS community. Lambda has become a golden hammer though it's important to know how to use golden hammer properly. Once people starts understanding how to use it, they see golden nails everywhere!

With AWS Lambda, I have heard a lot of stories about what you can do and lessons to build an event-driven architecture. But I want to hear what are the part of architecture where you should absolutely not use serverless aka antipatterns. Here are few of what I have come across:

* async calls * too many dependencies * redundant functions * too much granularity * shared code * tight coupling