03. Backend
The part of a web app that runs on a server, not in the user’s browser. Handles data, logic, authentication, and anything that needs to be trusted or kept secret. In a modern Next.js app, the line between “frontend” and “backend” is blurry — this section covers what’s on the server side of that line.
Entries
| # | Entry | Status | One-line description |
|---|---|---|---|
| 1 | What is a backend? | 🟩 COMPLETE | The “trusted” half of an app — runs on servers, hides secrets, owns data |
| 2 | APIs — the big picture | 🟩 COMPLETE | What an API actually is and the families of API styles |
| 3 | REST APIs | 🟩 COMPLETE | The most common pattern: GET, POST, PUT, DELETE on URLs |
| 4 | GraphQL | 🟩 COMPLETE | An alternative to REST where the client describes the data it wants |
| 5 | Node.js | 🟩 COMPLETE 🟦 LIVING | The JavaScript runtime that lets JS run on servers |
| 6 | Serverless functions | 🟩 COMPLETE | Code that runs on demand, spins up only when called, scales to zero |
| 7 | Edge functions | 🟩 COMPLETE | Serverless code that runs close to the user, geographically |
| 8 | Next.js server actions | 🟩 COMPLETE 🟦 LIVING | The “form submits to a server function” pattern, integrated into React |
| 9 | Webhooks | 🟩 COMPLETE | ”Reverse” APIs — an external service POSTs to your endpoint when something happens |
Suggested reading order
1 → 2 → 3 (or 4) → 5 → 6/7 → 8 → 9. The first three are essential; the rest you grab as you encounter the relevant tools.
See also
- 02. Frontend — the other side of the wire
- 04. Databases — what your backend usually talks to
- 07. Security & auth — most security work happens on the backend
- 06. Hosting & deployment — where your backend actually runs