I am a Full Stack Developer skilled in React, Node.js, and mongoDB & System Design

Saikat Maji  • Peerlist

Engineered a full-stack AI-powered environmental intelligence platform aggregating real-time IoT sensor data and weather-pattern APIs to generate location-based alerts. - Reduced average API response time by 60% through multi-layer caching strategy and targeted MongoDB query indexing under concurrent user load - Designed a responsive React.js SPA dashboard with real-time Chart.js visualizations monitoring air quality and environmental risk thresholds across multiple metrics - Deployed via CI/CD pipeline (GitHub Actions) on Vercel with automated build and zero-downtime release flow - Integrated multiple third-party REST APIs for weather data aggregation with normalized data schemas Tech: React.js · Node.js · Express.js · MongoDB · REST APIs · Chart.js · Vercel · GitHub Actions · CI/CD

EnviroGuardian

Architecting an enterprise-grade full-stack banking web application covering account management, fund transfers, transaction history, and Razorpay Payment Gateway integration. - Designing atomic MongoDB schemas for accounts and audit logs to prevent race conditions and double-spend vulnerabilities in concurrent financial operations - Implementing Razorpay webhook listeners for real-time payment - Building Jest unit and integration test suites for end-to-end data integrity verification across all critical financial workflows - Secured with JWT refresh-token rotation + bcrypt password hashing + RBAC multi-tier access control for role-based permissions Tech: MongoDB · Express.js · React.js · Node.js · JWT · bcrypt · Razorpay API · Jest · Webhook Integration

SecureBank — Full-Stack Banking System

Building a real-time bidirectional chat and live device tracking application using Socket.io WebSocket protocol and HTML5 Geolocation API with Leaflet.js live map visualization. - Architecture designed to handle 10+ concurrent WebSocket connections via event-driven, non-blocking Node.js backend optimized for high-concurrency scenarios - Implementing JWT refresh-token rotation for secure session management. - Integrating HTML5 Geolocation API with Leaflet.js interactive maps for live multi-user device tracking with real-time position updates - Mobile-first React.js frontend with lazy loading and Core Web Vitals optimization for fast, smooth user experience across devices Tech: React.js · Node.js · Express.js · MongoDB · Socket.io · WebSocket · Leaflet.js · JWT · HTML5 Geolocation API