A real incident
A women's safety app left its photos and messages open to anyone with the link, and the chapters next door are the seven layers that would have caught it.
The chapters
49 min total
- Frontend7 minYou see a screen as three materials, turning a diff of edits into moves you can steer.
- Backend7 minYou run three tests to decide what needs a server, or whether the build needs one at all.
- APIs7 minYou read an API call line by line and turn one request's token cost into the monthly bill.
- Data7 minYou pick the smallest storage that fits and separate stored records from the per-turn prompt.
- Hosting7 minYou compare hosting options, read a pricing page, and track the two bills an AI product pays.
- Auth7 minYou separate who-you-are from what-you-may-do and write the three-line spec that gates access.
- Monitoring7 minYou write a one-sentence spec: the worst silent failure, the signal, and where the alert lands.
The sum
Put the layers together and you can trace any product end to end: what the user touches, what the server holds, what each answer costs, who gets in, and how you hear it broke before users do.