Available for freelance work

Hi, I'm Amit Kumar

Backend / Full Stack Developer

I build scalable SaaS and AI-powered applications — from high-performance backend systems to polished user-facing products.

View Projects

Open to work

3+Years Experience

18+Projects Shipped

13+Happy Clients

20+Technologies

Featured Projects

A selection of products I've built — from SaaS platforms to AI-powered systems.

OTT Streaming Platform

Full-featured video streaming platform with HLS multi-quality playback, subscription tiers, user auth, and a comprehensive admin panel with analytics.

Node.jsReactMongoDBExpress+3

Live Demo

Certificate Generation SaaS

Multi-tenant SaaS for dynamic certificate generation with custom templates, bulk PDF rendering via Puppeteer, email delivery, and a REST API for third-party integrations.

Node.jsReactAWS S3Puppeteer+1

Live Demo

AI RAG Knowledge System

LLM-powered Retrieval-Augmented Generation pipeline with vector semantic search. Reduces hallucination by 70%+ with citation tracking and streaming responses.

LangChainOpenAIVector DBFastAPI+1

Live Demo

More Projects

Cricradio

Cricket Scoring Platform

Live Demo

End-to-end cricket scoring ecosystem built — comprising a real-time scoring mobile app, a public match-tracking website, and a scoring admin panel. Features a cascading update mechanism that keeps ball-by-ball, over, innings, and match totals perfectly in sync, plus ETag caching to cut redundant API traffic.

Node.jsReactReact NativeMongoDBRedisWebSockets

Caprics Learning

LMS Platform

Live Demo

Full-featured Learning Management System with a student mobile app, teacher portal, and parent dashboard — all managed through a unified admin panel. Supports course creation, live classes, assignment tracking, progress reports, and in-app communication across all three user roles.

Node.jsReactReact NativeMongoDBMulti-tenancyAWS S3

E-Commerce Platform

Full-Stack Store with Payments

Live Demo

Feature-rich e-commerce platform with product catalog, search & filters, cart, wishlist, Stripe & Razorpay payment integration, order tracking, inventory management, and a seller dashboard with sales analytics.

Node.jsReactMongoDBStripeRazorpayRedis

Skills & Technologies

Technologies I use to build production-grade systems from backend to AI.

Backend

Node.js90%

Express.js88%

NestJS78%

REST APIs92%

Frontend

React85%

Next.js82%

TypeScript80%

Tailwind CSS88%

Database

MongoDB88%

PostgreSQL75%

Redis78%

Prisma ORM72%

Cloud & DevOps

AWS (EC2, S3, Lambda)70%

Docker72%

Nginx68%

GitHub Actions (CI/CD)72%

AI & LLM

LangChain78%

LLM (OpenAI) API82%

Vector Databases75%

RAG Pipelines80%

Work Experience

My professional journey building backend systems and full-stack products.

Software Engineer

Current

OnGraph Technologies

Full-time · On-site

Oct 2025 – PresentNoida, Uttar Pradesh, India

Developing and maintaining an OTT streaming platform with multi-tier subscription management — handling plan upgrades, downgrades, renewals, and grace-period logic.
Implemented robust error and failure handling across the payment flow — covering gateway timeouts, webhook retries, partial failures, and idempotent transaction recovery.
Built a payment analytics dashboard tracking revenue, churn, failed transaction rates, and subscription conversion funnels using aggregated pipeline queries.
Integrated app insights and monitoring — capturing API latency, error rates, and user engagement metrics to surface actionable observability across services.
Designed and maintained MongoDB schemas with optimised indexing strategies for high-throughput subscription and billing operations.

Node.jsMongoDBOTTSubscriptionsPayment AnalyticsMonitoring

Full Stack Developer

Lifease Solutions LLP

Full-time · 1 yr 2 mos

Aug 2024 – Sep 2025On-site

Owned end-to-end delivery of key features, ensuring stability, performance, and on-time deployment across project phases.
Designed and implemented a cascading update mechanism in the cricket scoring system to maintain data consistency across nested score events.
Implemented ETag-based caching to eliminate redundant API traffic and measurably improve response times.
Reduced MongoDB read load by leveraging Redis as an in-memory cache layer, ensuring faster data retrieval under peak traffic.
Designed an efficient data-storage and sync strategy in Redis to keep cached records updated in sync with MongoDB changes.

Node.jsReact.jsMongoDBRedisETag Caching

MERN Developer

Todquest Enterprises

Full-time · 10 mos

Nov 2023 – Aug 2024On-site

Implemented a Multi-Tenancy Architecture for an LMS — securely isolated user data, optimised resource allocation, and improved overall scalability and performance.
Authored Node.js migration scripts to automate a full data migration from MySQL to MongoDB with zero data loss.
Identified and resolved critical cross-module bugs while handling large datasets through accurate CSV parsing and efficient bulk database imports.

Node.jsReact.jsMongoDBMySQLMulti-tenancyLMS

React & Node Developer

Cyberspace Networking Systems Pvt Ltd

Apprenticeship · 8 mos · On-site

Dec 2022 – Jul 2023Delhi, India

Developed and maintained full-stack web applications across both frontend (React, Next.js) and backend (Node.js) layers.
Built responsive UI components and integrated REST APIs to deliver end-to-end feature functionality.

JavaScriptNext.jsReactNode.js

Get In Touch

Have a project in mind or want to collaborate? I'd love to hear from you.

amit208201@gmail.com

Drop me a message anytime

linkedin.com/in/amit-k

Connect with me professionally

GitHub

github.com/tima99

Explore my open source work

Ready to build something great?

Whether it's a SaaS product, AI integration, or a full-stack app — let's make it happen.

Send me an email