Backend Engineer Roadmap

The path from "I can write an endpoint" to "I got the job" - and you practice each step on a real broken service in a live cloud workspace. Every skill links to a live ticket you fix.

Your progress0 of 12 skills

APIs & HTTP Fundamentals

Status codes & REST

Return the right 4xx/5xx and shape a correct response.

Practice live: Return the Correct HTTP Status Code → CORS & headers

Ship the middleware so the browser stops blocking your API.

Practice live: Add CORS Middleware to an Express API →

Databases & SQL

Indexing slow queries

Find the missing index and turn a slow endpoint fast.

Practice live: Index a Slow Postgres Query → The N+1 query

Collapse hundreds of per-row queries into one join.

Practice live: Fix the N+1 Query →

Authentication

JWT auth

Authenticate an API with signed, expiring tokens.

Practice live: Add JWT Authentication to an API → Auth bugs

Fix a JWT check that accepts any token.

Practice live: Fix a JWT Auth Bug That Accepts Any Token →

Reliability & Concurrency

Connection pools

Plug a pool leak that exhausts the database.

Practice live: Plug a Postgres Connection Pool Leak → Race conditions

Stop a double-charge under concurrent requests.

Practice live: Stop a Double-Charge Race Condition →

Performance & Caching

Cache the hot path

Add a cache to the read path and cut latency.

Practice live: Cache a Hot Read Path With Redis → Rate limiting

Cap the API with a rate limit that holds under load.

Practice live: Add a Rate Limiter to an API →

Scaling & Architecture

Zero-downtime migrations

Add a NOT NULL column with a safe backfill, no downtime.

Practice live: Add a NOT NULL Column With a Zero-Downtime Backfill → Distributed transactions

Ship an order saga with compensating actions.

Practice live: Build an Order Saga With Compensating Actions →

Stop reading roadmaps. Start doing them.

Every skill above is a real broken system in a live workspace. Fix it, and it lands on your portfolio.

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