Denis V.

Hi👋🏻 I'm a Senior AI Full Stack Developer with 6+ years of experience building SaaS products, MVPs, and AI-powered web applications with Node.js, NestJS, Next.js, React, TypeScript, and Supabase. From the first idea to a stable production release, I own the full stack: backend, frontend, database, API integrations, and deployment. AI-ASSISTED, HUMAN-OWNED 🤖 I use AI tools to speed up web development, but every line of code and every architecture decision goes through my own careful review. AI drafts, I engineer and take responsibility for the result. You get the speed of AI-assisted full stack development in Node.js, NestJS, React, Next.js, TypeScript and Supabase with the quality, security, and maintainability of an experienced full stack developer. TRACK RECORD 📊 ✔ 6+ years in full stack web development with Node.js, NestJS, Next.js, React, and TypeScript ✔ 26 successful projects across 7 industries ✔ 18 satisfied clients, from early-stage founders to growing businesses ✔ Full ownership of product quality, from architecture to production WHAT I BUILD 🧩 • SaaS platforms: multi-tenant SaaS with subscriptions, Stripe and PayPal payments, role-based access (RBAC), and admin dashboards on Node.js, NestJS, Next.js, React, and Supabase • SaaS MVPs: a launch-ready MVP built with Next.js, React, TypeScript, and Supabase, deployed to Vercel / AWS / DigitalOcean • Marketplaces: two-sided marketplaces and booking platforms with search, reviews, Stripe Connect, and PayPal payouts • CRM and ERP systems: internal tools, customer portals, and business dashboards built with React, Next.js, Node.js and NestJS • AI-powered web applications: OpenAI API, Claude API, and other LLM APIs for AI agents, RAG, chatbots, document processing, and workflow automation • Web scrapers and parsers: reliable web scraping, data parsing, and data pipelines on Node.js with scheduled jobs and clean storage in PostgreSQL or MongoDB • Custom web applications: full stack web apps with a Node.js / NestJS backend and a React / Next.js frontend, shaped around your business logic APIs AND INTEGRATIONS 🔌 I design and build REST APIs and RESTful API backends with Node.js and NestJS, and connect your product with third-party services through API integrations: Stripe, PayPal, QuickBooks, Xero, Google APIs, OpenAI API, Claude API, webhooks, and OAuth / SSO authentication. Every integration is typed in TypeScript, tested, and documented. FIX, REFACTOR, SHIP 🛠️ • AI-generated and vibe-coded apps: code review, bug fixing, security fixes, refactoring, and preparing the app for production • Existing Node.js, NestJS, Next.js, or React projects: architecture review, bug fixes, performance improvements, and new features without unnecessary rewrites • Supabase and Firebase: authentication, Postgres, row-level security, storage, and realtime features for your SaaS • Scaling: PostgreSQL and MongoDB optimization, Redis caching, background queues, and infrastructure on AWS or DigitalOcean TECH STACK 💻 Backend: Node.js, NestJS, TypeScript, REST API / RESTful API, webhooks Frontend: React, Next.js, TypeScript, JavaScript, Tailwind CSS Databases: PostgreSQL, Supabase, Firebase, MySQL, MongoDB, Redis Payments: Stripe, PayPal AI: OpenAI API, Claude API, LLM APIs, AI agents, RAG Cloud and DevOps: AWS, Vercel, DigitalOcean, Docker, CI/CD, GitHub Actions, Git, GitHub PRODUCTS I BUILD ✔️ SaaS platforms, SaaS MVPs, AI-powered web applications, marketplaces, booking platforms, CRM and ERP systems, dashboards, customer portals, web scrapers, and API-driven business apps. Each one is end-to-end full stack web development with Node.js, NestJS, React, Next.js, and TypeScript. LET'S TALK 📩 Book a free 30-minute call. We'll go through your idea or your existing Node.js, React, or Next.js codebase, define the MVP scope or the key technical risks, and agree on the stack and plan. You speak directly with the full stack web developer who will build your product. Need a full stack developer or full stack web developer for a SaaS, an MVP, a marketplace, an AI-powered web application, or an API integration? Send me your goal and current stack, and I'll reply with a clear plan and next steps.