Sanjay Kumar M.

I help startups and businesses build SaaS platforms, full-stack web applications, Python backend services & React Native mobile apps from launching an MVP to improving and scaling an existing product. With 8+ years of hands-on software development experience, I work across the complete application stack: frontend interfaces, backend architecture, databases, authentication, APIs, third-party integrations & production deployment. My primary technologies include React, Next.js, TypeScript, Node.js, NestJS, Python, FastAPI, PostgreSQL, Supabase & React Native. I also work with Kotlin and Swift for native Android and iOS development, along with C#/.NET for supporting backend development and existing applications. What I Can Help You With: - SaaS & MVP Development: Multi-tenant applications, subscription billing, admin dashboards, role-based access, customer portals and scalable backend architecture. - Full Stack Web Development: React/Next.js frontends, Node.js/NestJS backends, authentication, database architecture and third-party integrations. - Python Backend Development: FastAPI services, REST APIs, backend integrations, automation scripts, data processing and AI-powered applications. - Mobile App Development: Cross-platform iOS and Android apps using React Native and Expo, along with native Android development using Kotlin and native iOS development using Swift. - Backend & API Development: RESTful APIs, authentication, PostgreSQL, SQL databases, background processing, third-party integrations and performance optimization. - AI Integrations & Automation: OpenAI, Claude, AI chatbots, RAG-based search, LLM-powered features and workflow automation. - C#/.NET Support: Smaller backend features, API integrations, debugging and maintenance tasks within my experience. - Existing Application Development: New features, bug fixes, codebase refactoring, performance improvements and application modernization. - Cloud & Deployment: AWS, Docker, CI/CD, Vercel and production infrastructure. Relevant project experience I've worked on products across SaaS, business management, travel, healthcare, real estate & mobile applications. I'm comfortable joining an existing development team, taking ownership of a specific feature, or handling a complete application from architecture through deployment. Whether you need a full-stack developer, Python/.NET backend support, API development or help improving an existing application, feel free to share your requirements. I'd be happy to discuss the technical approach and next steps. Keywords: SaaS Development | SaaS Product Development | SaaS MVP Development | SaaS Application Development | SaaS Architecture | Multi-Tenant SaaS | B2B SaaS Development | SaaS Platform Development | MVP Development | Startup MVP Development | Full-Stack SaaS Developer | Web Application Development | Mobile App Development | Marketplace Development | AI Application Development | AI Integration | AI SaaS Development | React Developer | Next.js Developer | Node.js Developer | NestJS Developer | React Native Developer | TypeScript Developer | Backend Development | API Development | .Net Development | Python Development | REST API Development | Scalable Backend Architecture | PostgreSQL Development | MongoDB Development | Redis | Admin Dashboard Development | RBAC | Role-Based Access Control | Workflow Automation | Business Process Automation | Payment Integration | Stripe Integration | Subscription Billing | API Integration | Third-Party API Integration | Booking Platform Development | Healthcare Software Development | HIPAA-Compliant Development | Fintech Software Development | Real Estate Software Development | E-commerce Development