What is bffpattern?

The BFF pattern stands for “Backend‑For‑Frontend”. It is an architectural style where you create a small, dedicated backend service that is tailored specifically for the needs of one type of client application (like a mobile app, a web SPA, or a smartwatch). Instead of letting every client talk directly to the same large API, each client gets its own “backend for frontend” that aggregates data, formats responses, and handles client‑specific logic.

Let's break it down

  • Client - the UI you see (mobile app, web page, etc.).
  • BFF - a thin server that sits between the client and the core services.
  • Core services / microservices - the main business APIs that hold data and logic. The client sends a request to its BFF. The BFF may call several core services, combine the results, reshape the data, and send a single, optimized response back to the client. This keeps the client code simple and reduces the number of network round‑trips.

Why does it matter?

  • Performance - fewer calls and smaller payloads mean faster load times, especially on mobile networks.
  • Simplified client code - the UI doesn’t need to know how to stitch together many APIs; it just talks to one endpoint.
  • Security & versioning - the BFF can enforce client‑specific auth rules and hide internal API changes from the front‑end.
  • Team autonomy - front‑end and back‑end teams can evolve independently because the BFF acts as a contract.

Where is it used?

  • Mobile apps that need data from several microservices in one screen.
  • Single‑page web applications (React, Angular, Vue) that want a single, tailored API.
  • IoT devices or wearables with limited bandwidth.
  • Companies adopting micro‑service architectures who still need a simple API surface for their UI teams.

Good things about it

  • Reduces latency by aggregating multiple calls into one.
  • Allows response shaping (e.g., removing fields the client doesn’t need).
  • Provides a place to implement client‑specific caching, rate limiting, or feature flags.
  • Keeps front‑end code clean and focused on UI, not on data orchestration.
  • Makes it easier to evolve core services without breaking the UI.

Not-so-good things

  • Adds an extra layer to maintain, which can increase operational complexity.
  • Potential for duplicated logic if many BFFs implement similar transformations.
  • Requires careful versioning; changes to the BFF can affect the client directly.
  • May become a bottleneck if not scaled properly, especially under high traffic.
  • Over‑engineering for very simple applications; a single shared API might be sufficient.