Take apart a full AI system, end to end
By the end of today you can open an unfamiliar modern AI application, say what every piece does and why, name what would break first, and argue the alternatives. That was the point of all ninety days.
YesterdayNinety days: how code runs, data structures, the web, backends and databases, production engineering, system design, AI engineering, and agents. Today they meet at once.
TomorrowNothing follows. What you review from here is chosen by what you rated weakest, not by a schedule.
Why this matters
This is the promise the curriculum made on Day 1: not that you would have built a portfolio, but that you could read any system and understand it. Today is where you find out whether that happened.
- Reading a whole system
- Questions to ask of code
- Isolating a failure
- Tradeoff reasoning
Learn it
70 minCopy this into Claude or ChatGPT. It quizzes you before it explains anything, which is deliberate. The resources under it are how you check what it told you.
Today's Master Prompt
Free · sign inA prompt written for this day alone: your level, the exact scope, what to leave out, and an instruction to quiz you before it explains anything. Paste it into Claude or ChatGPT and it teaches you today's material.
Check it against something that is not a model
An assistant can be fluent and wrong, and on a topic you met today you will not catch it. These cover the same ground and were made by people who do this for a living, so they are what you hold the explanation up against. They are other people's work and we only link to them, so judge them for yourself.
3 hand-picked resources
Free · sign inVideos, official docs and articles covering the same ground, each opened and annotated by hand. They are what you check the assistant against on a day you cannot yet catch it being wrong.
Build it
60 minFind a real open-source AI application on GitHub, one you have never seen. Spend forty-five minutes producing a written review: what it does, its main path, its weakest component, its security exposure, what breaks at scale, and what you would change first. Then compare it against the review you would have written on Day 1.
Recall it
20 minAnswer out loud, reveal, then mark honestly whether you had it. That score is the only thing on this page you do not get to choose.
5 recall questions
Free · sign inQuestions you answer from memory, then grade yourself against the real answer. The score is carried into the mastery rating below it, so an honest miss cannot quietly become a tick.
Rate it
Completion and mastery are tracked separately. Be honest, because an inflated rating only means the concept resurfaces sooner.
Mastery tracking
Free · sign inRate yourself against five named criteria per concept. Completion and mastery are tracked separately, and anything you rate shakily comes back automatically on a spaced schedule.
Recap
- 01You can open unfamiliar software and say what it does and why
- 02You know what breaks first, and how you would confirm it
- 03You can name the tradeoffs, including the ones you would have made differently
- 04The weakest three areas are yours to keep working on; nothing schedules that now
Your progress
Free · sign inMark days complete, pick up where you left off across devices, and watch completion and mastery diverge. Free, and the account exists only so ninety days of work cannot vanish with a cleared browser.