Most application teams never fine-tune anything — and ship great products anyway. Knowing when it actually pays (and when it's an expensive detour) is the senior skill. That's all this page installs.
Four rungs, cheapest first. Tap a rung to see what it buys — and what it costs.
Exhaust the cheap rungs first. What pushes you up a rung should be a failing eval — not vibes.
Tap a card to flip it. Two honest columns.
The classic line, worth memorizing: fine-tune for behavior, RAG for knowledge.
Tap to flip. One line each — the intuition, zero math.
Pick the symptom you actually have. Get the boring, correct answer.