Divyansh D.

Full-Stack & Mobile App Developer | SaaS, MVP & AI | React, FastAPI

Top Rated full-stack and mobile developer. I build web and mobile apps, SaaS MVPs, and AI features end to end, one senior engineer, shipped in weeks not quarters. React, React Native, Next.js, FastAPI. 5+ years building live SaaS products, including B2B AI platforms for enterprise clients. Most early-stage teams burn months coordinating three contractors who don't talk to each other: a backend dev, a frontend dev, and an AI specialist, each owning a piece but nobody owning the product. I'm one senior full-stack engineer who handles the entire stack from architecture to deployment, so your MVP ships in weeks instead of quarters. WHERE I ADD THE MOST VALUE ▸ You have a SaaS product and want to add AI features (chatbot, document processing, intelligent workflows) without breaking what already works. ▸ You're a founder who needs a full product, frontend, backend, AI integration, and deployment, built by one reliable engineer. ▸ You need LLM features that are production-hardened: streaming responses, fallback handling, cost optimization, and real error recovery. ▸ You want fast delivery without accumulating technical debt. WHAT I BUILD ▸ Full-Stack SaaS Platforms: End-to-end SaaS development using Next.js, React, FastAPI, and Java Spring Boot. Auth (NextAuth, JWT), Stripe payments, role-based dashboards, multi-tenancy, and REST/WebSocket APIs. ▸ LLM-Powered Applications: Chat interfaces, AI assistants, document Q&A (RAG), automated workflows, and voice-enabled AI apps using OpenAI, Claude API, LangChain, and LlamaIndex. Integrated directly into your product, not bolted on as an afterthought. ▸ API Development & Third-Party Integrations: Clean RESTful APIs with FastAPI or Spring Boot. Integrations with OpenAI, Anthropic, Stripe, Twilio, Agora, ElevenLabs, Azure Cognitive Services, and more. ▸ Mobile Apps (Android & iOS): Native Android apps in Java/Kotlin and cross-platform solutions with React Native. Real-time sync, offline support, and AI-powered features built in. ▸ Database & Backend Architecture: PostgreSQL, MongoDB, Supabase, Redis. Schema design, query optimization, and backend architecture that scales as your user base grows. ▸ Cloud Deployment & DevOps: Docker, Azure, AWS, Vercel, Firebase. CI/CD pipelines, environment configuration, and production deployment, not just "it works on my machine." RECENT PROJECTS AI Interview Platform (Supercoder): Built a real-time AI interviewer using LLMs, voice synthesis (ElevenLabs), and Microsoft Speech-to-Text. Deployed on Azure for B2B clients in South Korea. Handles live interview sessions with automated evaluation and scoring. Sarva Health AI (Healthcare B2B SaaS): Built an AI-powered Revenue Cycle Management platform for healthcare automating medical billing to cut claim denials, speed up reimbursements, and improve operational efficiency. Full-stack build with Next.js, FastAPI, and LLM-driven automation, deployed to production. Tooth Fairy (Dental Video Consultation, iOS + Android): The UK's first dental video calling app, built with dentists. Patient and dentist apps on both platforms: live video consultations, appointment booking, in-app payments, and prescription requests. The hard part was keeping calls reliable on poor mobile connections and handling patient data properly for a UK healthcare product. TECH STACK AI / LLM: OpenAI API · Claude API · LangChain · LlamaIndex · ElevenLabs · Whisper · Azure OpenAI Backend: FastAPI · Java Spring Boot · Node.js · REST APIs · WebSockets · JWT · OAuth2 Frontend: Next.js · React.js · TypeScript · Tailwind CSS · ShadCN · Redux Mobile: Android (Java / Kotlin) · iOS · React Native Database: PostgreSQL · MongoDB · Supabase · Redis · Prisma ORM Cloud & DevOps: Azure · AWS · Vercel · Firebase · Docker · CI/CD WHY CLIENTS WORK WITH ME AGAIN ▸ I ask the right questions before writing a single line of code ▸ I communicate clearly, no ghosting, no vague updates ▸ I flag problems early instead of hiding them until the deadline ▸ I care about your product working, not just your ticket being closed ▸ I write code that the next developer can actually read and maintain LET'S TALK Send me a message, or invite me to the job, and I'll respond fast, usually within the hour. If it's a fit, we move fast.