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Architecture
API gateway vs reverse proxy vs CORS proxy: what each one does
API gateway vs reverse proxy vs CORS proxy compared: who each serves, what it does, where they overlap, and how to choose the right one for your architecture.
6 min read Read -
Rate limiting
API rate limiting for frontend developers: 429s and Retry-After
Understand API rate limiting from the browser: what 429 and Retry-After mean, how to read rate-limit headers cross-origin, and how to retry with backoff and jitter.
6 min read Read -
CORS
CORS preflight requests explained: when and why OPTIONS happens
What triggers a CORS preflight request, how the browser and server negotiate it, how Access-Control-Max-Age caches it, and how to fix the failures you'll see.
6 min read Read -
CORS
Debugging CORS errors step by step in Chrome and Firefox DevTools
A repeatable routine for debugging CORS errors: read the console, find the preflight in the Network panel, compare headers, and reproduce the request with curl.
5 min read Read -
CORS
How to fix 'No Access-Control-Allow-Origin header is present'
Read the exact CORS error, find out whose server has to change, and pick the right fix: configure the API, add a backend, use a dev proxy or a CORS proxy.
5 min read Read -
Security
Signed URLs explained: HMAC signatures, expiry and replay protection
How signed URLs work: HMAC signatures, canonical forms, expiry, method binding, nonces and replay protection, with working signing and verification code.
6 min read Read -
CORS
What is CORS? A practical guide for frontend developers
Why browsers block cross-origin requests, how preflight works, how to read the CORS error in your console, and the three ways to fix it.
4 min read Read