8.1The Serverless Testing Challenge

Serverless functions run in environments you do not control. You cannot SSH into the machine, you cannot inspect the filesystem, and you cannot attach a debugger in production. The execution environment is ephemeral -- it exists only for the duration of the invocation.

This means your testing strategy must be more rigorous than traditional application testing. If you miss a bug in a serverless function, your only debugging tools are logs and traces. There is no "let me quickly check on the server."