but you don’t need to refactor everything at once, next time a test breaks, refactor that specific test. spread the word at the company, so they stop doing the old way and more people help to do the refactor… one day it all gonna be done.

both clauses expect a :amount key that is not present in the map that is passed as argument.

edit: not sure if your question is about the error or a better way to format this.
in the way you’re using it, it would be better to have a struct or at least use the dot notation to extract the values instead of pattern matching them on function clause:

def build(something) do
  created_at = something.created_at
  ...
end

Having not used LLMs myself, if that doesn’t work you might have some luck with Sourceror depending on how consistent your map assertions are.