Glossary term
What is BFF (Backend For Frontend)?
BFF stands for Backend For Frontend.
In System Design
A small API layer tailored to one type of client. Example: A mobile BFF returns compact data; a web BFF returns detailed data.
Learn it properly · System DesignLesson 13: Reverse Proxy vs API GatewayReverse proxy, load balancer and API gateway get used interchangeably — NGINX is called all three. What each one is actually for, where authentication and rate limiting belong, the Backend-for-Frontend pattern, and when a gateway is overkill.In The Browser Contract
A server you own between the browser and other APIs. It keeps the tokens, so the browser only holds a session cookie.
Learn it properly · The Browser ContractLesson 3: Where Do Tokens Live? XSS, CSRF and the Storage Trade-offlocalStorage lets XSS steal tokens. Cookies let CSRF attacks use you. Safe patterns: HttpOnly cookies with SameSite or CSRF tokens, access tokens kept in memory, and a backend-for-frontend.