Pick the Right Model
Match the model to the task's depth: fast models for narrow edits, deeper models for tangled work.
A quick rename doesn't need the same model as a cross-cutting refactor. Faster models (Haiku) handle narrow, well-specified tasks cheaply; deeper models (Sonnet, Opus) earn their cost on ambiguous, multi-file, or reasoning-heavy work. Say which model to use, and why, so the trade-off is explicit.
Where you'll practice this
One Promptles scenario teaches this principle directly.
Pick the Right Model
You need to rename a single exported function in `src/utils/date.ts` from `formatDate` to `formatShortDate`, and update every caller in the repo. It's a mechanical, well-scoped change. The default model in your assistant is Opus, which is overkill — it'll be slower and more…