The Claude Certified Developer Foundations (CCDV-F) exam does not reward recall. It hands you a scenario, a support desk that must answer ten thousand tickets by morning, a dashboard that chokes on prose, a ticket with hidden instructions, and asks you to make a developer’s decision. Every item on it asks one of four decisions. What runs. How does it call Claude. What does Claude see and say. Will it survive production. The quarters are real: computed from the skill weights in the current official exam guide, each decision covers roughly a quarter of the 53 items. The course stamps the decision on every worked question, so by the end you read stems the way the item writers built them.
Two elimination rules do the rest, and both are extracted from the official sample rationales rather than invented. The constraint rule: every stem names its binding constraint, cost, overnight, reuse, untrusted input, and the credited answer is the mechanism built for exactly that constraint. Any option that turns a generic knob, temperature, max_tokens, a bigger model, one more line in the prompt, is a distractor. The guarantee rule: when a stem says must, never, always or cannot, guidance loses to mechanism. A polite system-prompt line is advice. A hook that blocks the action, or a schema the output is validated against: that is enforcement. All three published sample questions fall to one of these two rules.
