FULL-STACK & BACKEND ENGINEER
Your backend,built to scale.
Esmattoha Mondal helps product teams ship reliable, high-performance applications — from API architecture to production deployment.
WHAT I HELP WITH
The problems I solve for your team
Whether you're a startup building your first product or a scaling company dealing with performance bottlenecks — here's where the work happens.
APIs That Don't Break Under Pressure
When your user base grows 10x overnight, your backend shouldn't become a liability. REST and GraphQL APIs are designed for high concurrency, with caching layers and queue management to keep everything responsive.
Data That Scales With Your Business
Poorly designed schemas cost companies thousands in migration work later. Database architecture is built with growth in mind — whether that's MongoDB document design, SQL relational modeling, or hybrid approaches.
Infrastructure That Runs Itself
Deployment should be boring. CI/CD pipelines, AWS configurations, and Docker containerization ensure your application ships reliably and recovers automatically when something unexpected happens.
End-to-End, Without the Handoff Friction
Frontend and backend teams that don't communicate cost time. Having delivered across the full stack means bridging that gap — ensuring the API contract matches what the UI actually needs.
Product Backends for SaaS & Retail
High-transaction systems like POS platforms demand zero tolerance for errors. Real-world experience building production POS software for the electronics industry means the edge cases have already been fought through.
Authentication That Protects Your Users
OAuth flows, JWT handling, session management — security is not an afterthought. Auth systems are implemented to protect both your users and your business from day one.
FEATURED WORK
Things built that are live in production
Real products, real users, real scale. Every project here has gone through the full cycle — from architecture decisions to production deployment.
POINT-OF-SALE PLATFORM — ELECTRONICS RETAIL
Lunix POS
A retail chain needed a POS system capable of handling thousands of daily transactions across mobile, laptop, and accessories sales — without slowdowns during peak hours.
- →Scalable Node.js backend architecture built to sustain high transaction volumes
- →Optimized database operations to reduce query latency during concurrent sales
- →Seamless frontend-backend integration for real-time inventory and sales updates
E-COMMERCE BACKEND — B2C MARKETPLACE
Tradelia
An e-commerce platform required a robust booking and order management backend that could handle real-time stock updates, email/SMS notifications, and OAuth-secured user accounts at scale.
- →Full REST API suite redesigned and rewritten in TypeScript for long-term type safety
- →Redis-powered caching and queue system for reliable, high-speed email and SMS delivery
- →OAuth authentication and Mongoose schema design for complex product and booking data
SAAS PRODUCT — MOBILE APP BACKEND
Tnyl
A SaaS mobile application needed a high-performance backend that could support a growing user base with reliable authentication, structured data, and fast API response times.
- →TypeScript REST APIs built for performance and long-term maintainability
- →MongoDB schemas designed with scalability and query efficiency in mind from day one
- →OAuth integration for secure, seamless user authentication across devices
Want to see more context on any of these?
Get in touch →CAREER TIMELINE
6+ years of building systems that work
A track record across startups, product companies, and agencies — each role adding a new layer of depth to what's possible.
Lunix POS
CurrentBackend Engineer
May 2023 – Present
Building and maintaining the core server infrastructure for a production POS platform used by electronics retailers. Focus areas include transaction reliability, system performance under load, and backend-to-frontend API contracts.
Astria Digital Pvt. Ltd.
Backend Engineer
Apr 2023 – Mar 2024
Contributed to backend systems for client-facing web and mobile applications. Worked across Node.js, AWS, SQL, and MongoDB to deliver scalable server-side logic and data management solutions.
Netsqure Technologies Pvt. Ltd.
Full-Stack Developer
Jan 2023 – Mar 2023
Worked across WordPress custom theme and plugin development and contributed to a PHP-based CRM application — gaining experience in both CMS customization and enterprise-level data management tools.
Tradelia Technologies Inc.
Backend Developer
Mar 2020 – Dec 2022
Core backend contributor for a B2C e-commerce platform over nearly three years. Designed flexible REST APIs, built scalable database schemas, rewrote critical booking APIs in TypeScript, and contributed to frontend work in Vue.js.
Foxflue Network Pvt. Ltd.
Backend Developer
Jan 2019 – Mar 2020
Began career building production backend services. Gained early hands-on experience with Nest.js and Fastify, establishing a strong foundation in API development and server-side architecture.
TECHNOLOGY
The tools behind the work
Chosen for reliability, performance, and real-world production readiness — not because they're trendy.
Runtime & Frameworks
Node.js, NestJS, Fastify, Express
Languages
TypeScript, JavaScript, PHP
Databases
MongoDB, MySQL, PostgreSQL
Cloud & DevOps
AWS, Docker, Git, CI/CD
Frontend
Nuxt.js, Vue.js, Next.js
APIs & Auth
REST, GraphQL, OAuth, JWT
ABOUT
Behind the code
There's a specific kind of problem that surfaces when a product starts gaining traction — the backend begins to crack. APIs slow down, databases become unpredictable, and the team is spending more time putting out fires than shipping features. That's the problem this work is built around.
With six years of experience across startups and product companies, the focus has always been on one thing: making sure the systems underneath your product are solid enough to support your ambitions. From the first API endpoint to production-grade infrastructure on AWS — the entire backend lifecycle is familiar territory.
When not in the code, there's time spent thinking about architecture patterns, performance tradeoffs, and how to make the next project ship faster than the last one.
Years Active
Companies
Projects Shipped
LET'S WORK TOGETHER
Have a project in mind?
Whether it's a new product that needs a backend built from scratch, an existing system that's hitting performance limits, or a team that needs a senior engineer for a few months — let's figure out if there's a fit.
Send a Message Or connect on LinkedIn →