Spec-Driven Development

Describing software to an AI works beautifully until the software gets big enough to matter. Then something quiet goes wrong. The assistant fills every gap you left with a guess, it never mentions that it guessed, and by the time you notice, the guesses are load-bearing. You did not get what you wanted. You got exactly what you asked for.

Spec-Driven Development is the discipline that fixes this, and it is the first course in the advanced track. You will learn why plans beat prompts once a project passes a few hundred lines, what actually belongs in a specification and what does not, why the section listing what you are not building is the most valuable one you will write, how to state “done” in terms a machine can check, and how to hand a spec to an AI in pieces without the work quietly drifting away from the plan.

Taught in plain language with clear diagrams and small, honest examples, and it is tool-agnostic: the discipline holds whichever assistant you use. It builds on prompting, testing and version control. Each module blends a short video overview, illustrated lessons, a knowledge-check quiz, and a hands-on interactive activity, including a build simulator where the code drifts away from the spec and you have to notice.

What you will be able to do:

• Recognise the point where prompting stops scaling and planning takes over.
• Find the unstated decisions hiding inside an innocent one-line feature request.
• Write the six parts of a specification, including the non-goals.
• Turn vague wishes into acceptance criteria a machine can check.
• Break a spec into tasks and build them one at a time, reviewing against the spec rather than against your mood.
• Know when the spec is wrong and should be changed, and when the code is wrong and should be fixed.

Who it is for: Builders who can already get an AI to write working code, and who have been surprised by what it decided on their behalf. Best taken after prompting, testing and version control.

Course outline: Orientation · Why Plans Beat Prompts · Anatomy of a Spec · Writing Acceptance Criteria · From Spec to Code · Capstone: A Spec You Can Build From.