Welcome to my portfolio

Hello, I'm
Pappu Kumar

I'm a_

Crafting high-performance scalable systems and robust full-stack solutions with modern technologies. Let's turn your complex ideas into efficient digital reality.

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Years Experience

10+

Projects Completed

About Me

Learn more about my Journey

Education

B.Tech

CSVTU

2018 - 2022

Intermediate of Science

JDS (+2) School Khilwat

2018

Matriculation

Cambridge Public School Patna

2015

My Story

Hello! I am Pappu Kumar, a Software Engineer with ~2 years of professional experience specializing in building backend-heavy full-stack systems. My core expertise lies in designing robust backend systems using Node.js, Next.js and scaling complex applications.

I have strong experience in designing REST APIs, implementing secure authentication workflows, and integrating seamless payment gateways. My work involves handling sensitive financial data and ensuring compliance in fintech domains like loans and insurance.

Beyond the backend, I have solid frontend exposure using React and Next.js, allowing me to deliver complete end-to-end features. I am comfortable bridging the gap between database schema design and user interface implementation.

I thrive on building real-time communication systems and optimizing performance for high-load environments. Whether it's containerizing services with Docker or deploying on AWS, I enjoy the entire lifecycle of software development.

My Philosophy

Technical Core Values

Scalability First

Designing systems that grow with demand, ensuring high availability and seamless expansion.

Security by Design

Implementing robust security protocols and encrypted workflows to safeguard user data.

Efficient Performance

Optimizing every line of code and database query for lightning-fast response times.

Experience

10+

Projects

Global Reach

10,000+

Coding Hours

My Timeline

Professional Experience

Software Engineer

Matriot Solutions

03/2023 – 03/2024

Bengaluru, Karnataka

Joined as the first engineering hire post-COVID to stabilize and rebuild a legacy IoT platform handling real-time sensor data and alert notifications.
Upgraded frontend from React 16 to React 18 and refactored class components into functional components using Hooks, improving performance and maintainability.
Implemented Redux Toolkit for efficient state management and streamlined API handling.
Enhanced UI using Bootstrap, SCSS, and Material UI, and developed dynamic dashboards for real-time sensor data visualization and consumption trends.
Resolved dependency issues and stabilized local development environment for both frontend and backend.
Built WebSocket-based real-time data streaming for live device monitoring.
Developed and enhanced RESTful APIs using Node.js and Express.
Led database migration from MongoDB to MySQL, transforming nested data structures into optimized relational schemas.
Improved database performance through query optimization and indexing strategies.
Refactored tightly coupled backend modules using an event-driven architecture with Node.js EventEmitter to improve modularity and scalability.
Implemented Redis queue-based batch processing for database writes, reducing load from high-frequency IoT device data.
Scaled system to support 10,000+ devices using Docker-based horizontal scaling, Nginx IP hashing for session stickiness, and Redis adapter for WebSocket synchronization.
Resolved duplicate MQTT message processing issues using MQTT load-sharing techniques.
Containerized frontend, backend, and database services using Docker and Docker Compose for consistent deployment.
Configured Nginx as reverse proxy for traffic routing and improved reliability.
Created technical documentation for system architecture, local setup, and Docker-based deployment.

Founding Engineer

SenseGrass

04/2024 – 05/2025

Bengaluru, India

Designed and built end-to-end microservices architecture for a fintech platform using Node.js, PostgreSQL, RabbitMQ, gRPC, and React.
Developed full authentication system with OTP-based mobile login (Twilio), JWT-based web authentication, and RBAC authorization.
Designed two-layer API Gateway using Nginx (edge layer) and Express for routing, security, and load balancing.
Built payment orchestration system with webhook handling, idempotency protection, and event-driven workflows.
Designed and implemented event-driven notification service for SMS and email delivery using RabbitMQ, Twilio, and SendGrid.
Implemented centralized external integration service using Adapter pattern for payment, KYC, and verification providers.
Developed admin dashboard using React, Redux Toolkit, Tailwind CSS, and secure cookie-based authentication.
Containerized services using Docker Compose with health checks, retry mechanisms, and monitoring.

Founding Engineer

SenseGrass

06/2025 – Present

Bengaluru, India

Continued contributing in an equity-based capacity post full-time tenure.
Fixed production bugs, improved system stability, and optimized existing APIs.
Added incremental backend features and enhancements based on business needs.
Supported deployments, environment fixes, and production troubleshooting.
No exclusivity or conflict of interest; open to full-time opportunities.

My Portfolio

Featured Projects

Real-Time Multi-Party Video Calling Platform

Microservices System

Real-Time Multi-Party Video Calling Platform

Built a microservices-based real-time video conferencing platform supporting multi-party calls, screen sharing, and real-time chat using WebRTC + Mediasoup SFU architecture.

Designed distributed system with API Gateway, Signaling Service, and Media Service for scalability and separation of concerns.
Migrated internal service communication from REST to gRPC (Protocol Buffers) reducing latency from ~50ms to ~5ms.
Implemented low-latency media streaming pipeline using Mediasoup SFU with multi-core worker optimization.
Containerized services using Docker & Docker Compose for consistent development and deployment.
Deployed entire system on Google Cloud Platform (GCP) with containerized infrastructure.
Configured Nginx gateway for traffic routing and service orchestration.
Built production observability stack using Prometheus + Grafana + Consul for monitoring, service discovery, and health checks.
Implemented centralized structured logging with session tracking and browser-based log viewer.
Designed real-time messaging and signaling using Socket.io.
Designed system for horizontal scaling with future support for Redis Pub/Sub and multi-node media servers.