Concept from Avdi: pattern-input-work-result-failure
Another person talks about this here:
Guard clauses are like boundaries. We use them to get the stuff that happens after them to be more pure. (not a direct quote)
6:30 as soon as it enters your system you want to make structured at the barrier
6:50 "I really don't want to be passing this unstructured thing all around in my code. I want to have an explicit place where this conversion is happening."
At 22:30 don't pass the params/hash everywhere. Some people call the wrapping of that data form-objects.