Do you write evals before or after the prompt?

Genuine question for the room. We started writing ten eval cases before touching a prompt and it changed how we work — but it feels slow at the start. What is your order?

Before, always. A prompt without evals is a vibe.

After, honestly. I need to see what goes wrong first before I know what to test.

Both: five cases before, then every bug report becomes a case.