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SITE-APIJAStart learning

BACKEND LEARNING, REBUILT.

Go from “using” APIs to
designing and building them.

Turn your frontend experience into backend confidence.Write, send, fix, and pass—all inside one hands-on browser workspace.

Start your first exerciseSee how it works
  • No setup required
  • Preview Phase 1 without sign-in
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src/server.ts
GET /health
1import { createServer } from 'node:http'
2
3const server = createServer((req, res) => {
4  res.setHeader('content-type', 'application/json')
5  res.statusCode = 200
6  res.end(JSON.stringify({ status: 'ok' }))
7})
8
9server.listen(3000

LEARNING AT A GLANCE

7

PHASES

From fundamentals to operations

750+

TASKS

Progressive implementation tasks

65

TOPICS

Concepts broken into clear steps

19

TICKETS

Real-world project work

WHY SITE-API

Beyond knowledge.
Build with confidence.

You can watch every video and read every guide, yet still freeze when the editor opens. The missing piece is not more theory—it is focused implementation with immediate feedback. site-api puts hands-on work at the center from the first minute.

01

CODE IN BROWSER

Go beyond reading

Write real server code in the browser, send a request, and inspect the response without leaving the workspace.

02

CLEAR FEEDBACK

Know exactly what passed

Deterministic checks validate the status, headers, and body—so “it seems to work” becomes clear evidence.

03

REAL PROJECT

Finish in a real context

Read an existing codebase and resolve bug reports and change requests, turning knowledge into engineering judgment.

THE LEARNING LOOP

Write it here.
Understand it here.

Read the spec. Change the code. Send the request. Confirm the result. This tight feedback loop turns understanding into practical skill.

  1. 01READStart from a realistic spec or bug report
  2. 02BUILDChange the actual code in the editor
  3. 03SENDInspect the HTTP request and response
  4. 04PASSClear every explicit grading check

TASK 1-03

Return a JSON response

03:42

When GET /profile is requested, return the specified JSON response.

name: "Mika"

role: "frontend"

YOUR CODE Run

const profile = {

name: 'Mika',

role: 'frontend'

}

GRADING RESULT

You passed

3 / 3 checks passed

  • status is 200
  • Content-Type is correct
  • body matches the spec
+ 20 XPNEXT TASK →

FROM LESSON TO PROJECT

Finish with the work
real teams actually do.

Step into the existing MiniMart codebase and work through implementation tickets. Read the requirement, trace the impact, and keep the test suite green—the skills you need beyond a tutorial.

Explore the project exercise

CURRICULUM

From zero to operations.
One connected path.

Start with raw HTTP, then move through CRUD, API contracts, databases, authentication, product design, and production operations in an order that always makes the next step clear.

PHASE 01HTTP Fundamentals and Raw ResponsesPHASE 02Routing and CRUD APIsPHASE 03API Contracts, Validation, Errors, and TestingPHASE 04Data Persistence and SQLPHASE 05Authentication, Authorization, and SecurityPHASE 06Product API Design and EvolutionPHASE 07Operations, Performance, and Capstone

65 topics plus a 800-problem practice catalog

View the full curriculum

START WITH ONE REQUEST

Run your first API
right here, today.

There is no environment to configure. In the first five minutes, you will start a server and return your first response.

Start with Phase 1