Practice path · 7 games

Foundations

Start with API semantics, route design, auth decisions, CORS, webhooks, OAuth, and secure recovery.

Best first path for CS students and new backend learners.

APIs Beginner

Choose the correct HTTP status code for realistic backend scenarios and learn the response semantics behind each answer.

APIs Beginner

Design REST-style methods and routes for product requirements such as creating users, updating email, searching products, and nested comments.

Auth Intermediate

Inspect authentication scenarios and choose safe backend decisions for tokens, scopes, sessions, CSRF, and object-level authorization.

APIs Intermediate

Guide browser API requests through CORS decisions covering origins, preflight, credentials, exposed headers, and cache safety.

APIs Intermediate

Investigate webhook requests and choose safe handling for signatures, replay windows, retries, idempotency, and durable acknowledgement.

Time: 6-9 minutes
Concept: Webhook verification, replay protection, idempotency, and retry-safe processing

Auth Advanced

Trace Authorization Code flow failures across state, PKCE, redirect URI, token exchange, and session boundaries.

Auth Intermediate

Secure account recovery against enumeration, token theft, replay, concurrent use, and stale sessions.