Sahil User

I’m a Backend Engineer with 3+ years of experience building scalable backend systems, REST APIs, microservices, and cloud-native applications using Node.js, NestJS, TypeScript, and AWS. I focus on designing secure, production-ready architectures that can handle real-world usage.

In my current role, I designed and developed backend services and real-time APIs with PostgreSQL, MongoDB, Redis, WebSockets, and AWS. I built authentication and authorization with RBAC, implemented well-documented REST APIs using Swagger/OpenAPI with API versioning and rate limiting, and integrated OAuth providers and services like QuickBooks, Zoom, Stripe, and Brevo.

I also specialize in scalability and reliability through event-driven processing—using Redis caching, BullMQ queues, RabbitMQ messaging, retry mechanisms, and asynchronous workflows. I improved performance by optimizing database queries and adding caching where it mattered.

I enjoy taking ownership end-to-end, from CI/CD pipelines (GitHub Actions, ArgoCD) to production deployments on AWS, Railway, Vercel, and DigitalOcean with Nginx and SSL. My projects range from a multi-tenant ADR platform to an AI-powered HR Policy Assistant (RAG, LangChain, ChromaDB, and LLM integrations).