Senior Node.js Backend Engineer & API Architecture Specialist for High-Load Applications

We are seeking a highly experienced Senior Node.js Backend Engineer with deep expertise in building scalable, secure, and high-performance backend systems. The ideal candidate must have extensive knowledge of Node.js, Express.js/NestJS, microservices architecture, distributed systems, data modeling, API design standards, real-time communication, caching strategies, and cloud deployment pipelines.

Your core responsibilities will include architecting and implementing REST APIs, designing database schemas for both SQL and NoSQL environments, managing complex business logic, and optimizing backend performance for large-scale applications that handle thousands to millions of requests per day. You must be proficient in writing modular, testable, and reusable code, implementing clean architecture principles, and managing enterprise-level codebases with multiple services and dependencies.

You will build highly optimized API endpoints, implement secure input validation, handle complex query operations, integrate third-party services, and design asynchronous workflows using queues (BullMQ, RabbitMQ, Kafka). Deep knowledge of promises, async/await, event-driven architecture, error-handling flows, retry strategies, rate limiting, and throttling is required to maintain reliability under high-traffic conditions.

You will manage authentication and authorization using JWT, OAuth 2.0, API tokens, session-based authentication, RBAC/ABAC user management, and zero-trust principles. You must implement security best practices, including protection against SQL injection, NoSQL injection, XSS, CSRF, SSRF, command injection, insecure headers, sensitive data exposure, broken authentication, and improper session handling.

Performance optimization will be a major part of your work. You will diagnose slow endpoints, reduce latency, implement caching layers (Redis, Memcached), optimize database queries and indexes, reduce response payloads, configure HTTP compression, and benchmark performance using profiling tools. Scaling strategies such as cluster mode, load balancers, horizontal scaling, containerization using Docker, orchestration using Kubernetes, and cloud deployment (AWS, GCP, Azure) are highly important.

You will be responsible for designing microservices or modular monolith structures, handling service discovery, inter-service communication, API gateways, message brokers, event buses, and circuit breakers. You must ensure fault tolerance, monitoring, observability, and graceful degradation across all backend components.

You will maintain strong CI/CD pipelines with automated testing (Jest/Mocha), linting, environment configuration, secret management, migrations, versioning, and orchestrated deployments. You must interpret logs from tools like PM2, Winston, Morgan, Elastic Stack, Datadog, or CloudWatch to diagnose live issues.

Responsibilities include documenting APIs using Postman Collections or Swagger/OpenAPI 3.0, managing versioned endpoints, implementing pagination strategies, supporting mobile and web clients, and enforcing strong API contracts. Experience with WebSockets, Socket.io, SSE, or GraphQL subscriptions is a strong advantage.

Candidates should have experience with production systems, microservice ecosystems, real-time applications, financial-grade security environments, or large-scale cloud infrastructure. You must be able to collaborate with frontend, mobile, DevOps, QA, and product teams while maintaining clean, maintainable, future-proof backend architecture.

Only apply if you have built or contributed to high-load, production-grade Node.js backends. GitHub repositories, architecture diagrams, performance metrics, or production project links are highly preferred.