Lesson 25 / 25

Revision: Cheat Sheet and Self-Check

Review the habits, risks and workflows from the whole course.

Cheat sheet

Modes: completion, chat, agent; more autonomy needs more review. How it works: predicts plausible code, does not verify it. Prompting: give files, exact errors and constraints; write tests first; ask for small steps. Workflows: explain, write, debug, refactor with tests green before and after. Review: hallucinated APIs, off-by-one and empty cases, injection and secrets, read the diff, break the code to test the tests. Safety: no secrets in prompts, check policy and licences, agents on a branch with limited permissions, content from outside is data. Learning: attempt first, understand always. Teams: shared guide, author owns the code, measure outcomes.

Questions interviewers ask

Be ready to explain: how coding assistants work and why they can be confidently wrong, how you review AI-written code, how you use tests to guide an assistant, what you never paste into a prompt, and how you keep learning while using AI tools.

Quick check: An assistant's generated tests all pass. What should you still do?

  • Nothing, green means correct
  • Delete the tests
  • Break the code on purpose to confirm the tests can fail
  • Ask the assistant to say they are fine
Answer

Break the code on purpose to confirm the tests can fail — Green tests only help if they would turn red when the code is wrong.

Quick check: Which of these should never be pasted into an assistant prompt?

  • A production database password
  • A public function signature
  • A generic error message
  • A question about syntax
Answer

A production database password — Credentials must stay out of prompts because prompts leave your machine.

Quick check: You do not understand a block of generated code. What is the best next step?

  • Commit it, it probably works
  • Delete the tests
  • Hide it in a comment
  • Ask the assistant to explain it and verify by running it, or simplify it
Answer

Ask the assistant to explain it and verify by running it, or simplify it — You are responsible for every line you commit, so understand it or replace it with something you do.