i found a lot difficult, like:

  - how to structure my code, esp wrt callbacks/ step functions
  - are there any conventions? like, what should my handler be called?
  - uploading libraries (into/via layers) was stupid
  - no ability to decomission lambdas -- you just gotta delete 'em
  - finding lambdas was painful; the console was slow
  - linking them to api gateways and configuring was painful

i'm still a fan of the general concept, but once i got past 'hello, world', the dev cycle slowed down tremendously.