Professional freelance work and client contributions (no proprietary code included).
Hi, I'm Nishal, a Freelance Full-Stack Developer with 1+ years of experience building scalable APIs, end-to-end web applications, and production-ready services. I specialize in health-tech, fintech, and civic engagement platforms, delivering robust backend systems that handle real-world business challenges.
This repository showcases my freelance journey, highlighting the measurable impact I've created for clients, the complex technical problems I've solved, and the architectural decisions that drive business success.
- Role: Freelance Full Stack Developer
- Backend Expertise: Node.js, FastAPI (Python), Express.js, RESTful & GraphQL APIs
- Database & ORM: MySQL, PostgreSQL, Sequelize, SQLAlchemy, Redis
- Frontend Integration: React, Next.js, TypeScript, TailwindCSS
- DevOps & Deployment: Docker, Fly.io, Vercel, Database Migrations
- Integrations: Razorpay Payments, JWT/OTP Auth, Email Services (Nodemailer), AI/ML (YOLOv8, OpenCV)
- Documentation & Testing: Postman Collections, OpenAPI Specs, Comprehensive READMEs
- 🏥 Health-tech Impact: Built authentication & insurance application APIs serving live users on Aarogya Sampark
- 🌱 Civic Innovation: Launched Sweepzy, a gamified environmental platform with AI-powered litter detection
- ⚡ Performance: Reduced API error rates and improved system reliability through robust validation and error handling
- 🔒 Security: Implemented production-grade JWT + OTP authentication flows with secure session management
- 💰 Payments: Integrated Razorpay payment gateways with webhook handling, retries, and refund workflows
- 📊 Analytics: Built comprehensive admin dashboards and reporting systems for operational visibility
Click a project to see details (each project has its own README).
- Production-ready REST/GraphQL APIs with comprehensive authentication (JWT, OTP, OAuth)
- Database architecture, schema design & migration scripts (Sequelize, raw SQL)
- Payment integration (Razorpay, Stripe) with secure webhook handling
- Multi-level systems (referrals, commissions, wallet management)
- Third-party API integrations and microservice architecture
- Performance optimization, query tuning, and caching strategies
- AI/ML integration (YOLOv8, OpenCV) for computer vision features
- Real-time features and concurrency handling
- Containerization (Docker) and cloud deployment (Fly.io, Vercel)
- Comprehensive API documentation (Postman, OpenAPI)
- Database migration strategies and rollback-safe deployments
- Developer onboarding materials and integration guides
- Production-ready REST/GraphQL APIs with authentication (JWT, OTP flows)
- Database schema design & migration scripts (Sequelize / raw SQL)
- Robust validation, error handling, and logging
- API documentation and Postman / OpenAPI specs
- Troubleshooting & performance fixes for backend services
Ready to build something amazing? I'm available for freelance projects and would love to discuss how I can help solve your technical challenges.
- Email: nishaldevadiga2003@gmail.com
- LinkedIn: https://www.linkedin.com/in/nishaldev
- Portfolio Website: https://nishal-devadiga-portfolio.vercel.app/
- Response Time: Usually within 24 hours
What I can help with:
- Backend API development and optimization
- Database architecture and migration strategies
- Payment integration and financial workflows
- AI/ML integration for real-world applications
- Performance optimization and scalability planning
This repo contains only documentation, architecture notes, and non-proprietary examples of the work I did for clients. Live/production code for client projects remains the property of the client and is not shared here.