Backend developer. I build REST APIs with Node.js, PostgreSQL, MongoDB and Redis.
I care most about the parts that are easy to get wrong: checkout under concurrency, token rotation and payment webhooks. The case studies below show the decisions, the bugs I found in my own code and the numbers I measured.
Projects
E-Commerce Backend API
A store backend where two buyers cannot take the last unit and a payment is never settled twice.
Checkout takes a Redis lock and then decrements stock with an atomic MongoDB update guarded by $gte, rolling back if any item fails. Refresh tokens are single use and stored as SHA-256 hashes. Razorpay webhooks are verified against the raw body with HMAC-SHA256 and deduplicated in Redis. It has 103 integration tests, and a self-audit found five bugs that I fixed and wrote up.
- Node.js
- Express 5
- PostgreSQL
- Prisma
- MongoDB
- Mongoose
DevJournal
A learning journal with public and private journeys, spaced-repetition reviews and a paid Pro plan.
People write entries in Markdown with tables and Mermaid diagrams, share them by link or keep them private, follow each other and get notifications. Reviews come back on a spaced-repetition schedule, with streaks and a heatmap. Groq formats entries and suggests tags. The code is private.
- Next.js 16
- MongoDB
- Google OAuth
- GitHub OAuth
- JWT
- Razorpay
Services
- REST API development
- I design and build APIs with Node.js and Express on PostgreSQL or MongoDB, with authentication, pagination, validation and integration tests.
- Payment and webhook integration
- I integrate Razorpay checkout and webhooks with signature verification on the raw body, duplicate event handling and transactional settlement, so a retry never charges or fulfils twice.
- Backend review for performance and security
- I read an existing backend for race conditions, missing auth checks, unsafe defaults and slow paths, then give you a written list of findings with fixes in priority order.
For freelance work, use the form below and tell me what the API needs to do.
Skills
- Languages
- JavaScript
- Backend
- Node.js, Express, REST API design, JWT authentication with refresh token rotation, Razorpay webhooks, Zod validation
- Databases
- PostgreSQL (Prisma), MongoDB (Mongoose, Atlas Search), Redis
- Tools
- Vitest, Supertest, Git
I also build front ends with React, Next.js and Tailwind CSS when a project needs one.
About
I am a B.Tech Computer Science student at Guru Jambheswar University of Science and Technology Hisar, graduating in 2028. Most of what I build is backend: APIs, data modelling, authentication and payments. I write integration tests and audit my own code before I call something finished, and I write down what I find, including the results that did not go the way I expected. I am looking for a backend internship and I take on freelance API work. I am based in Hisar.
Contact
Tell me about the role or the project. I read every message and reply by email.