Key points
- Concrete input/output examples are the most effective way to communicate a transformation when prose is read inconsistently; two or three usually suffice.
- Test-driven iteration: write the tests first, then share failing output to steer each round.
- The interview pattern has Claude ask questions up front to surface considerations you had not anticipated.
- Report interacting problems in a single detailed message; fix independent problems sequentially.
- A specific test case with example input and expected output is the clearest bug report, for example a null value in a migration script.
Skills the exam expects
- Provide 2-3 input/output examples when descriptions produce inconsistent results.
- Write test suites covering expected behavior, edge cases and performance before implementation, then iterate on failures.
- Use the interview pattern in unfamiliar domains to surface things like cache invalidation and failure modes.
- Supply targeted test cases to fix edge-case handling.
- Decide between one combined message and sequential fixes based on whether the issues interact.
Common misconceptions
- "If Claude misunderstood, write a longer prompt." More words rarely remove the ambiguity that examples would.
- "Write tests after the code so they match." Tests written first define the target instead of confirming the result.
- "One issue at a time is always clearer." Interacting fixes can undo each other when done separately.
Watch for
- A fourth rewrite of a description that has already failed three times.
- Vague bug reports such as "handle nulls properly" with no expected output.
- Implementing in an unfamiliar domain without surfacing the design questions first.
Practice task 3.5
54 practice items cover this task in CCA Prep Studio: flashcards, matching, scenario questions and explain-it-back exercises, each tracked toward your mastery score.