Simplifying API Communication with the BFF Pattern in NextJS

In one of my recent projects, the frontend had to juggle 5 different APIs, each having a different response schema. This issue of multiple backends has now become a common struggle as modern web applications often rely on multiple APIs, microservices, and third-party integrations. While this architecture is powerful, it can introduce complexity for the frontend, such as handling multiple data sources, managing authentication, and dealing with inconsistent response formats.

This is where the Backend-for-Frontend (BFF) pattern comes in. Instead of letting the frontend talk to all APIs directly, you place a thin backend layer between them. With Next.js, this pattern fits naturally, thanks to its API routes and server-side rendering (SSR) capabilities. If you’ve ever struggled with messy API responses or token handling on the client, you’ve already felt the need for a BFF layer.

In this article, we’ll explore what the BFF pattern is, why it matters, and how you can implement it effectively using Next.js.

What is the Backend-for-Frontend (BFF) Pattern?

The Backend-for-Frontend (BFF) pattern is an architectural approach where a dedicated backend layer is created specifically for a frontend application (e.g., web, mobile, or desktop).

Instead of having the frontend communicate directly with multiple microservices, APIs, or databases, the BFF acts as an adapter that:

• Orchestrates data from multiple sources.
• Shapes the responses to suit frontend requirements.
• Manages authentication and authorization.

In short, the BFF provides a single, tailored API surface that makes frontend development faster and simpler.

What are the benefits of this pattern?

• Simplified frontend logic: Since the BFF layer acts like a proxy, the UI only needs to interact with one API.
• Optimized payloads: Only the necessary data is returned.
• Improved security: Tokens and credentials are handled on the server, not the client.
• Flexibility: Each frontend (web, mobile, IoT) can have its own tailored BFF.
• Consistency: The BFF ensures a unified response format across diverse backend services.

Enough of the theory, I believe we now have some understanding of what the BFF pattern is and what benefits it provides. Next, let’s look through some code samples to see how we can implement this pattern using Nextjs.

Implementing the BFF Pattern with Next.js and NestJS

Architecture

• Frontend (Next): Renders UI and interacts only with the BFF layer.
• BFF Layer Next API Routes: Acts as a proxy between the frontend and backend.
• Backend Nest: Provides domain logic, connects to databases, and exposes microservices.

For the backend, we can have different services running as multiple instances of Nest application, each backend service handles different business domains such as auth, inventory, notification, etc.

Sample NestJS controller

// auth.controller.ts import { Controller, Get, Param } from '@nestjs/common'; import { AuthService } from './auth.service'; @Controller('auth') export class AuthController { constructor(private readonly authService: authService) {} @Get('user/:id') async findUserById(@Param('id') id: string) { return this.authService.findUserById(id); } } 

A service would be:

import { Injectable } from '@nestjs/common'; @Injectable() export class AuthService { async findUserById(id: string) { // Mocked DB call return { id, name: 'Alice', email: 'alice@example.com' }; } } 

Backend runs at http://localhost:4000/auth/user/:id.

Frontend

Next.js BFF API Route

// api/profile.ts import type { NextApiRequest, NextApiResponse } from 'next'; export default async function handler(req: NextApiRequest, res: NextApiResponse) { const { id } = req.query; const response = await fetch(`http://localhost:4000/auth/users/${id}`); const user = await response.json(); // Define a response structure independent of the backend. // You can also provide client-side fallbacks or mock responses based on contracts. // This allows you to implement client-specific logic and maintain flexibility. // Shape response for the frontend  res.status(200).json({ id: user.id, displayName: user.name, contact: user.email }); } 

Call BFF inside a component

// pages/dashboard.tsx import { useEffect, useState } from 'react'; export default function Dashboard() { const [profile, setProfile] = useState<any>(null); useEffect(() => { async function loadProfile() { const res = await fetch('/api/profile?id=123'); // single API  const data = await res.json(); setProfile(data); } loadProfile(); }, []); if (!profile) return <p>Loading...</p>;  return ( <div> <h1>Welcome, {profile.displayName}</h1>  <p>Email: {profile.contact}</p>  </div>  ); } 

Frontend is now no longer coupled with backend, we have the ability to enhance the BFF layer as well as connect to different backend source in order to fulfil any frontend UI requirements.

The real win here is that your frontend team stays focused on UI, while the BFF quietly handles API messiness, security, and data shaping in the background.

Key Takeaways

• Reduces Coupling Between Frontend and Backend
  • The frontend only talks to the BFF, not to multiple microservices directly.
  • If backend APIs change, only the BFF layer is updated — the frontend remains untouched.
  • This reduces the risk of frontend breakage and makes backend evolution safer.
• Manages Frontend Complexity
  • Instead of each component juggling multiple API calls, the BFF aggregates responses into a single, tailored endpoint.
  • Frontend developers can focus purely on UI/UX logic without worrying about data orchestration, token handling, or payload shaping.
  • Results in cleaner, more maintainable React/Next.js codebases.
• Adds Flexibility Across Platforms
  • Each frontend (web, mobile, IoT) can have its own BFF, optimized for its unique needs.
  • A mobile app might get lightweight, compressed data while the web app receives richer, more detailed payloads — all from separate BFFs pointing to the same backend.
  • The backend services remain consistent, while the BFF adapts to each frontend’s context.
• Enables Better Security and Governance
  • API keys, tokens, and sensitive logic stay in the BFF layer, never exposed to the client.
  • Centralized place for applying rate-limiting, logging, and caching policies.

Some use cases of the BFF Pattern

• E-commerce app: Imagine a product page that needs to pull in details, reviews, recommendations, and pricing. Without a BFF, your frontend would make four different API calls and stitch everything together. With a BFF, you ask one endpoint, and it delivers exactly what the UI needs in one go.
• SaaS dashboards: Dashboards are notorious for pulling data from everywhere, analytics, billing, user profiles, notifications. A BFF acts like the middle manager that gathers all the information, so your frontend doesn’t have to chase after five different services every time a page loads.
• Multi-channel apps (web + mobile): A web app might want the full dataset, while the mobile version only needs a trimmed-down payload for performance. With separate BFFs, you can shape responses differently for each client without touching the backend services.
• Microservices environments: If your system is split into many microservices like in my case, exposing them all directly to the frontend can get messy fast. A BFF hides that sprawl and presents a single, clean API to the UI.
• Third-party integrations: Ever had to deal with APIs like Stripe, Twilio, or Salesforce? They all come with different formats and authentication quirks. A BFF can normalize these responses and handle token management behind the scenes, so your frontend team doesn’t need to worry about it.

Conclusion

The Backend-for-Frontend (BFF) pattern provides a practical way to reduce complexity, improve security, and decouple frontend teams from backend changes. By introducing a thin adapter layer, the frontend gets exactly the data it needs in the right format, while backend services remain clean and independent.

As seen above, Next.js handles UI rendering and API orchestration, while NestJS focuses on core business logic and scalability, together striking a balance between developer productivity and system robustness.

If we were to push this setup further, we can consider doing

• Contract-First API Development with ts-rest
  • Ensures both frontend and backend share a strongly-typed contract.
  • Prevents mismatched API payloads and improves developer experience.
  • Example: Define your API in ts-rest once and generate client + server types.
• Authentication & Authorization with Cognito or Auth0
  • Offload user management, login flows, and token handling to battle-tested identity providers.
  • The BFF validates and refreshes tokens securely on behalf of the frontend.
  • Keeps sensitive credentials away from the client.
• Caching & Performance Enhancements
  • Add caching (e.g., Redis, edge caching with Vercel) to reduce API round-trips.
  • Improves frontend performance and backend scalability.
• Observability and Logging
  • The BFF is a perfect place to centralize logging, monitoring, and error reporting for frontend requests.