SUMIT KUMAR
Designing scalable backend systems and distributed architectures utilizing Event-Driven Microservices, Domain-Driven Design (DDD), CQRS, Event Sourcing, and Resilient Architecture, while integrating Stripe Connected Account/Paymongo payment flows and exploring agentic AI/ML structures.
func PublishEvents() {
events := db.GetOutbox()
for _, ev := range events {
broker.Publish(ev)
db.MarkSent(ev.ID)
}
}
About Me
Core Background & Expertise
Hello! My name is Sumit Kumar (Birwal). I design resilient, decoupled, and distributed software systems. My engineering focus lies at the intersection of robust backend patterns and secure web integrations.
I specialize in backend architecture utilizing Domain-Driven Design (DDD), CQRS, Event Sourcing, Event-Driven Architectures (EDA), and Resilient Architecture. I focus on transaction integrity and fault tolerance using patterns like the Inbox-Outbox Pattern with RabbitMQ to guarantee reliable event delivery. On the integration layer, I design payment architectures including Stripe Connected Account architectures and local gateways like Paymongo Philippines.
I am continuously improving my system design thinking, writing cleaner architectures, and exploring AI/ML agentic systems to solve real-world problems.
Backend Architecture
DDD, CQRS, Event Sourcing, Resilient Systems
Reliable Messaging
RabbitMQ, Inbox-Outbox Pattern, Saga
Payment Gateways
Stripe Connect, Localized E-wallets, Escrows
Problem Solving
Data Structures, Algorithms (C++/Python)
Professional Experience
My corporate journey, software engineering roles, and technical project execution.
Full Stack Developer @ Zenmonk Software & Services
NestJS & System Architectures • Mohali, India- Engineered highly scalable backend services using NestJS, Next.js, React, and TypeScript.
- Implemented core system architectures including Domain-Driven Design (DDD) and CQRS (Command Query Responsibility Segregation) to isolate workloads.
- Designed and executed Event Sourcing ledgers and transactionally secure event brokers using the Inbox-Outbox Pattern with RabbitMQ.
- Orchestrated inter-service async communication, containerizing domains via Docker into distributed microservices.
- Worked closely with senior architects in Agile environments, driving code reviews, testing routes in Postman, and merging branch components.
Node.js Developer @ Techbuilder
Node.js & Payment Systems • Mohali, India- Maintained scalable backend services in Node.js for a ride & food delivery platform (mobile app + web dashboard), supporting real-time orders.
- Integrated PayMongo and GWallet (Philippines) payment gateways and architected Stripe Connected Accounts for vendor/driver onboarding and automated payouts.
- Designed webhook-driven payment flows.
- Worked extensively with Git and GitHub (feature branches, pull requests, code reviews, merge conflict resolution) to ensure clean collaboration and stable production releases.
Software Developer Intern @ CodeQuotient
MERN Stack & Algorithms • Panchkula, India- Developed full-stack web applications utilizing the MERN (MongoDB, Express, React, Node.js) stack.
- Solidified basic algorithms, computer science paradigms, and database relations.
- Completed over 120+ Data Structures & Algorithms (DSA) challenges on LeetCode using C++ and Python.
- Coordinated with cohort engineering leads to test, debug, and launch responsive user interfaces.
Education
Academic degrees, institutional qualifications, and educational history.
Master of Computer Applications (MCA)
Bachelor of Computer Applications (BCA)
Class 12 (Senior Secondary)
Class 10 (High School)
Architecture Learning Journey
"Good Architecture Comes From Solving Real Problems."
Monolithic Beginnings
Started with traditional monolithic MERN stack projects using MVC structure. Faced tightly-coupled codebases, scaling bottlenecks, and coordinate conflicts.
Modular Monolith Shift
Gradually transitioned to modular architectures and domain isolation. Separated routers, controllers, and services to increase testability and manage features independently.
Scaling Out (Microservices)
Adopted Microservices architecture to isolate services, enable independent scaling, and isolate failure domains. Utilized RESTful communication and orchestrated containers with Docker.
Advanced Paradigms & Messaging
Deep-dived into robust messaging patterns: Domain-Driven Design (DDD), CQRS, Event-Driven Architecture, RabbitMQ exchanges (Direct/Topic/Fanout), and the Inbox-Outbox pattern for guaranteed delivery.
Resilient & Self-Healing Architecture
Designing fault-tolerant, self-healing distributed backends. Implementing resiliency patterns such as Retries with Exponential Backoff, Dead Letter Queues (DLQ) for message failure isolation, Circuit Breakers, Rate Limiting, and Idempotency.
Featured Projects
A showcase of technical repositories demonstrating advanced backend architectures, transaction patterns, payment engines, and AI/ML integrations.
LangChain AI Agent POC
An intelligent agentic POC exploring AI agent workflows using LangGraph and LangChain JS/TS, leveraging Google Gemini LLM API, memory layers, and custom tool binding architectures.
View Repository
Eternal Frames
A multi-tenant event photography gallery & studio management platform. Features subscription tier billing via Razorpay, modular NestJS DDD architecture, transactional Outbox pattern messaging with RabbitMQ, and a Next.js App Router frontend.
Deca Chat
A real-time multi-room messaging system built on NestJS Domain-Driven Design (DDD). Features WebSockets/Socket.io communication, public & room member management, transactional Inbox-Outbox message synchronization via RabbitMQ, and a weekly chat analytics dashboard.
C++ Custom Web Crawler
Built a web crawler in raw C++ using custom generic string, linked list, and hashmap libraries — completely avoiding external dependencies or standard string methods.
Custom C++ Library Suite
Designed and engineered generic C++ data structure and utility libraries from scratch, including custom implementation of HashMap, LinkedList, and String classes with manual memory management and optimized search-complexity bounds.
RabbitMQ Exchanges POC
A message routing architecture implementing Direct, Topic, and Fanout exchanges in RabbitMQ for asynchronous multi-service event orchestration.
AI Problem Analyzer
An intelligent engineering assistant using React, Express.js, and Google Gemini API to analyze system bug reports, utilizing Redis and BullMQ for task queues, and MongoDB for state tracking.
AI Resume Builder
An AI-powered profile and resume synthesis platform built with Node.js and Express.js. Uses FFmpeg to extract audio and Deepgram API (Nova-3 STT model) to transcribe pre-recorded speech, then leverages Google Gemini API (gemini-1.5-flash) to structure transcriptions into validated JSON profile data, backed by BullMQ/Redis async queues and MongoDB.
Core Skills & Technologies
Categorized layout of technologies, programming languages, and core software architecture designs I specialize in.
Architectural Paradigms
Languages & Backend
C++ (STL)
Python
JavaScript
TypeScript
Django
Java
NestJS
Node.js / Express
Databases & Infrastructure
MongoDB
MySQL
PostgreSQL
Redis
BullMQ
Socket.io
RabbitMQ
TypeORM
Mongoose
Docker
Linux (CLI)
Git & GitHub
AI, Agents & Specialized Tech
LangChain / LangGraph
Google Gemini API
Deepgram Voice STT
FFmpeg Processing
Frontend & Tools
HTML5 & CSS3
React
Next.js
Tailwind CSS
MUI
Redux & RTK
Zustand
Postman
HeroUI
Ant Design
React Hook Form
Zod
Payment Gateways
Stripe
Razorpay
Paymongo
Cloud & Hosting
Vercel
Render
Railway
Netlify
Achievements & Leadership
Key technical milestones, coding victories, and leadership initiatives that shaped my discipline.
Technical Milestones
1st Place – On-Spot Coding
Zerone24 IT FestCompeted in real-time to solve complex algorithmic puzzles under high pressure. Showcased strong logical layout and execution speeds.
2nd Place – On-Spot Debugging
Zerone24 IT FestDiagnosed, verified, and resolved runtime errors, design logic vulnerabilities, and syntax faults in competitive code layouts.
Community & Volunteering
NCC (National Cadet Corps) Cadet
School Service DivisionTrained in systematic physical discipline, defense values, and collaborative operations. Formed solid team-centric focus and resilience.
NSS (National Service Scheme) Volunteer
College Service DivisionContributed to civic campaigns, local welfare drives, and social welfare programs, developing strong soft skills and collaborative empathy.
Hobbies & Interests
What I enjoy doing when I am not coding or building distributed systems.
Cooking
Experimenting and preparing unique, creative dishes in the kitchen.
Watching Movies
Enjoying mind-bending sci-fi, cinema classics, and insightful documentaries.
Badminton
Engaging in energetic, fast-paced matches on the court.
Gaming
Casual relaxation and competitive match-ups with friends.
Get In Touch
Have an interesting project or opportunities you'd like to discuss? Drop a message!
Let's collaborate.
I am open to discuss full-stack engineering roles, system architecture design opportunities, and AI/ML project collaboration. Feel free to contact me through the form or direct networks.
Panipat, Haryana, India