How Software Actually Works, in 95 Seconds

With on-screen captions. Also on YouTube ↗.

AI writes code now. The scarce skill is steering: knowing where code lives, how it runs, and how it ships. You do not need to become a programmer to do that. You need the map. The class walks through it in seven layers plus a build day, with a live demo at each one. The video is the same map at speed.

1. Terminal - how you, and agents, talk to the machine. Every file has one address: its path.
2. Files - bytes plus a promise. Rename notes.md to notes.txt and the bytes don't change, only the promise does.
3. Apps - every app is a restaurant: frontend is the dining room, backend the kitchen, database the pantry, auth the keycard.
4. Browser - name, address, request, files, pixels. HTML is the skeleton, CSS the skin, JavaScript the muscle.
5. Deployment - localhost to break things, Vercel to go public, Supabase for memory and logins, Docker to box the whole machine.
6. Git and CI/CD - a time machine for folders, and robots that check every change before it ships.
7. Agents - AGENTS.md is always-on orientation; skills are runbooks loaded on demand. Both are plain text in the repo.
8. Build day - a todo app takes ten minutes by hand and under a minute by agent. The app is the tip; hosting, accounts, backups and security are the iceberg.

The video is code. It was built with Remotion, which renders React components frame by frame into an MP4. Every animation, from the typed terminal commands to the request packet travelling to the database and back, is a function of the frame number, so each render comes out identical. The colours and type are lifted from the class deck, so the video and the slides read as one piece.

The starting point was a CLAUDE.md for Remotion projects: a briefing file that teaches a coding agent the framework's rules. That is layer 7 of the class in practice. Hand the agent the map, and it can build the thing with you.

• How Software Actually Works - the full 54-slide class deck, with quizzes, checkpoints and speaker notes.
• The one-page handout - the eight-layer map on a printable A4 sheet.
• Talks & Trainings - other classes and training material.
• How Devin Fusion Ran a Five-Day Company-Brain Cutover - another explainer video made the same way, on what agents cost at scale.