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.

AK
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 — preview 1

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
Certificate Generation SaaS — preview 1

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
AI RAG Knowledge System — preview 1

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
More Projects
01

Cricradio

Cricket Scoring Platform

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
02

Caprics Learning

LMS Platform

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
03

E-Commerce Platform

Full-Stack Store with Payments

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.

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