Maksym K.

20+ years of software development, Master's in Computer Science, and a team of 15+ developers behind me. I don't just build interfaces - I build the product behind the business: React apps, backend systems, mobile apps, and architecture designed to survive growth. As a Full Stack Developer, React Developer, Node.js Developer and Mobile Developer, I bring a full engineering team when a project needs more than a single React developer - 70+ production-ready products delivered, $25M+ in value generated through architectural decisions, and 120K+ active users across shipped applications. FRONTEND & WEB 100+ products built across React.js, Next.js, React Native, TypeScript, JavaScript, Tailwind CSS, React Bootstrap, HTML5, CSS3, Redux and jQuery - achieving 30%+ faster rendering and 25%+ fewer steps in core flows. As a Frontend React Developer, react js developer, react next js developer, web app developer react and senior react developer, I turn Figma designs into responsive, maintainable, production-ready UI, designed with the backend in mind - APIs, data models, auth, security and scalability from the start. FULL STACK REACT & NODE 45+ SaaS platforms delivered using Node.js, React, Next.js, Supabase, PostgreSQL, Laravel, PHP, MySQL, MongoDB, Firebase and Stripe, cutting delivery timelines by 40%+ and query times by up to 55%. As a Full Stack Developer React Node, full stack developer saas, full stack developer crm, mern stack developer and node.js developer, I own REST APIs, integrations, authentication, role-based access control, business logic, real-time functionality, CRM/ERP dashboards, Ecommerce and B2B Marketplace platforms, payment systems, and cloud deployment - the full cycle from database architecture to production infrastructure. MOBILE, REACT NATIVE & EXPO 12+ mobile apps deployed to the App Store and Google Play, reaching 18K+ downloads. As a react native app developer, react native developer expo and mobile app developer, I build iOS and Android apps with React Native, Expo, TypeScript and Redux, backed by secure, scalable APIs - handling auth, payments, push notifications, subscriptions and deployment while sharing a reliable backend with web. AI & AUTOMATION 5+ AI products delivered, including systems processing 25M+ data pairs and 12K+ prompts, cutting manual research by 35%+. As an ai full stack engineer, full stack developer ai, full stack developer LLM and generative ai developer, I build with OpenAI, Claude API, ChatGPT, RAG, LangChain, Pinecone, FastAPI and Python - plus n8n for automating workflows and orchestrating AI pipelines, built directly into SaaS, CRM, ecommerce, healthcare and real estate platforms rather than bolted on. HEALTHCARE Healthcare Web Applications reaching 8K+ users and $150K+ in investment, with Clinic Management SaaS and Telehealth systems processing 450+ daily appointments and cutting no-shows by 18%+. As a full stack developer healthcare, healthtech full stack developer and react django developer, I handle video, chat, scheduling, RBAC and HIPAA-compliant architecture end to end. MARKETPLACE & ECOMMERCE 520+ orders processed, 45K+ listings, 1,400+ B2B products live. As a full stack developer marketplace, full stack developer ecommerce and shopify plus developer, I build Marketplace Platforms, B2B Marketplaces, Two-Sided Marketplaces and multi-vendor systems with Stripe, PayPal and Twilio integrations, driving 25%+ better lead quality and 30%+ higher conversion. FINTECH 480+ companies and 110K+ agents served across 60+ countries. As a full stack developer fintech and blockchain full stack developer, I build Fintech and PropTech MVPs with digital wallets, WebSockets, SSO, KYC flows and transaction logic - simplifying financial UX to drive 20%+ adoption growth and 35%+ higher retention. BROADER STACK 30+ projects spanning WordPress, Shopify, Angular, .NET, Flask, Vue.js, Svelte, Webflow, Symfony and MERN Stack, plus AWS, Google Cloud, Vercel, PostgreSQL, MongoDB, MySQL, GraphQL, Git and CI/CD - including full stack developer upwork, .net full stack developer and full stack developer webflow work. INDUSTRIES Healthcare & HIPAA-compliant systems, SaaS and enterprise apps, Ecommerce and CRM, B2B marketplaces, real estate platforms, booking systems, logistics dashboards, fintech, AI automation, and secure scalable backend infrastructure. DELIVERY & OWNERSHIP 70+ launches, 98%+ delivery rate, 6-18 month engagements. Whether you need a React Developer for a complex frontend, a Full Stack Developer React Node engineer, a React Native Developer, or a full team to take a product from idea to production, I cover UX/UI, Backend API, Data Architecture, integrations, mobile development, cloud deployment and DevOps support - architecture through production, with a team ready to scale when the project outgrows one developer.