Node.js's event-driven, non-blocking I/O model makes it the right choice for applications that need to handle many simultaneous connections efficiently — REST APIs serving mobile apps, real-time chat and notification systems, webhook receivers processing high volumes of events, and microservices that need low memory footprint. At Chulbul Design, we use Node.js with Express, NestJS or Fastify depending on project needs. We integrate with Razorpay, Cashfree, Shiprocket, WhatsApp Business API, Delhivery, and other Indian-market services that your application will need. We also build GraphQL APIs, WebSocket servers and event-driven architectures using Redis Pub/Sub or message queues for high-throughput workloads.
REST APIs & GraphQL — Built for Mobile, Web and Third-Party Consumers
A well-designed API is the difference between a product that is easy to extend and one that requires a full rewrite every time a new feature is added. We build Node.js REST APIs following OpenAPI 3.0 specifications — versioned, documented and consistent. Every endpoint has input validation (Joi/Zod), structured error responses, rate limiting and request logging. Authentication uses JWT with refresh token rotation or API keys depending on the consumer type. For products where mobile and web frontends need flexible data fetching, we build GraphQL APIs with DataLoader batching to prevent N+1 query problems. All APIs are load tested with k6 before delivery.
A logistics startup: Node.js API handling 50,000 webhook events per hour from courier partners with under 50ms median response time.
- OpenAPI 3.0 spec-first design with Swagger docs
- JWT / refresh token auth with Redis session store
- GraphQL with DataLoader for efficient data fetching
- Rate limiting, CORS, helmet security middleware
- k6 load testing — verified throughput before go-live
Real-Time Applications — Chat, Notifications and Live Data
Node.js is the platform of choice for real-time features because a single Node process can maintain thousands of open WebSocket connections simultaneously without consuming a thread per connection. We build real-time chat systems, live order tracking, instant notification systems and collaborative editing features using Socket.IO or native WebSockets. For push notifications, we integrate with Firebase Cloud Messaging (FCM) for Android/iOS apps and web push for PWAs. When real-time data needs to fan out to thousands of simultaneous users — live auction prices, match scores, stock tickers — we add Redis Pub/Sub as the broadcast layer so a single event source reaches all connected clients without database polling.
- Socket.IO real-time chat with rooms and presence detection
- FCM push notifications for Android, iOS and web
- Redis Pub/Sub for fan-out to thousands of connections
- Live order / delivery tracking with driver location updates
- Event-driven architecture with Bull / BullMQ job queues
Indian API Integrations — Razorpay, WhatsApp, Shiprocket & More
India-specific integrations are where many Node.js developers struggle — each API has its own quirks, webhook verification methods and edge cases. We have deep experience integrating Razorpay (orders, subscriptions, payouts, refunds), Cashfree (UPI Autopay), PhonePe PG, WhatsApp Business Cloud API (messages, templates, media), Delhivery and Shiprocket (shipment creation, tracking webhooks), NIC e-way bill API, GSTN e-invoice API, Aadhaar-based eKYC, and various Indian telecom OTP providers. We also build webhook verification, retry logic and dead-letter queues to ensure no event is lost even when downstream services are temporarily unavailable.
- Razorpay orders, subscriptions, payouts and refunds
- WhatsApp Business Cloud API — templates and chatbots
- Shiprocket / Delhivery logistics integration
- Webhook retry logic — no lost events during downtime
- GSTN e-invoice and NIC e-way bill API
150+
APIs & Backends Delivered
50ms
Median API Response
30+
Indian APIs Integrated
10+
Years Experience
Node.js Services We Offer
REST API Development
Versioned, documented REST APIs for mobile apps, web frontends and third-party integrations — with auth, validation, rate limiting and load testing included.
Microservices Architecture
Decompose monoliths into independently deployable Node.js microservices with Docker, inter-service communication via REST or message queues and centralised logging.
Real-Time Chat & Notifications
Socket.IO chat systems, live notification feeds, collaborative features and real-time dashboards — scaled with Redis Pub/Sub for thousands of concurrent users.
Payment Gateway Integration
Razorpay, Cashfree, PayU and PhonePe integrations with order creation, webhook handling, refund flows, payout disbursement and subscription billing.
Serverless & Cloud Functions
AWS Lambda or Google Cloud Functions in Node.js for event-driven workloads — image processing, PDF generation, scheduled jobs and webhook handlers that cost nothing when idle.
API Migration & Refactoring
Migrate legacy Node.js apps to NestJS, upgrade Express v4 to v5, add TypeScript to existing JavaScript codebases and refactor spaghetti routes into a maintainable architecture.
Our Node.js Development Process
Requirements & API Design
We define all endpoints, data models, auth flows and integration requirements in an OpenAPI spec before development starts.
Database Schema Design
PostgreSQL, MongoDB or MySQL schema design with indexes, relations and query optimisation planned before the first migration is written.
Development & Testing
TDD approach — unit tests written alongside code, integration tests for every endpoint, and automated test suite in CI pipeline.
Load Testing
k6 load tests simulate your expected peak traffic. We profile bottlenecks, add caching and optimise queries until the API performs under real load.
Deployment & Monitoring
PM2 or Docker deployment with zero-downtime restarts, error tracking via Sentry, and uptime monitoring so you know before your users do.
Need a Fast, Scalable
Node.js Backend?
Share your project requirements — new API, real-time feature, payment integration or legacy migration. We will review your architecture and provide a detailed technical proposal within 24 hours.