Yan K.

Hi! 🖐 I’m a MERN Stack & Full-Stack Developer specializing in React.js, Node.js, Next.js, TypeScript, MongoDB, Express.js and AI development. With 9+ years of experience and 500+ completed projects, I build scalable, high-performance web applications, SaaS platforms, dashboards, marketplaces, eCommerce solutions, CRM/ERP systems and AI-powered products. 🚀 📊 Key Metrics 9+ years in web development 500+ projects delivered 20+ technologies across frontend, backend, cloud & AI 100+ API & third-party integrations 10+ product categories Full-cycle development: Architecture → UI → Frontend → Backend → API → QA → Deployment ⚛️ Frontend React.js | Next.js | TypeScript | JavaScript | Redux | Redux Toolkit | Zustand | Context API | Tailwind CSS | Material UI I build responsive SPAs, dashboards, complex web applications, SSR/SSG solutions, reusable component systems and Figma-to-React/Next.js interfaces. 🟢 Backend Node.js | Express.js | REST API | GraphQL | WebSockets | Microservices Authentication, JWT/OAuth, RBAC, payment systems, webhooks, real-time functionality, background jobs and scalable APIs. 🍃 Databases MongoDB | PostgreSQL | MySQL | Redis | DynamoDB Database architecture, schema design, indexing, aggregation, query optimization and performance tuning. 🤖 AI Development I build and integrate: OpenAI API | LLMs | AI Chatbots | AI Assistants | AI Search | AI Recommendations | AI Automation | AI SaaS I can add AI functionality to existing React + Node.js applications or build AI-powered products from scratch. 📈 Performance & Analytics I work with: Lighthouse | Core Web Vitals | LCP | INP | CLS | TTFB | API response time | Database performance Optimization includes code splitting, lazy loading, caching, SSR/SSG, CDN, Redis, database indexing and API optimization. ☁️ Cloud & DevOps AWS | Azure | Google Cloud | Vercel | DigitalOcean | Docker | Kubernetes | Nginx | CI/CD I can take your application from development to production deployment and ongoing optimization. 🔌 Integrations Stripe | PayPal | Adyen | Twilio | Google APIs | Shopify APIs | REST | GraphQL | OAuth | Webhooks | Custom APIs 🏗️ What I Build 🔹 SaaS platforms 🔹 AI-powered applications 🔹 Dashboards & admin panels 🔹 Marketplaces 🔹 eCommerce platforms 🔹 CRM / ERP systems 🔹 Booking & scheduling platforms 🔹 Real-time applications 🔹 Healthcare & FinTech solutions 🔹 Customer portals My approach combines Frontend + Backend + Database + API + Cloud + AI, allowing me to understand and optimize the entire product — not just one part of it. 🔎 Keywords MERN Stack Developer, MERN Developer, Full Stack Developer, React Developer, React.js Developer, Node.js Developer, Express.js Developer, MongoDB Developer, Next.js Developer, TypeScript Developer, JavaScript Developer, Senior React Developer, Frontend Developer, Backend Developer, AI Developer, OpenAI Developer, LLM Developer, AI SaaS Developer, ChatGPT Integration, SaaS Development, Web Application Development, Dashboard Developer, CRM Developer, ERP Developer, Marketplace Developer, eCommerce Developer, REST API, GraphQL, API Integration, Microservices, WebSocket, AWS Developer, Docker, Kubernetes, PostgreSQL, Redis, Redux, Zustand, Tailwind CSS, SSR, SSG, SPA, JWT, OAuth, Figma to React, Figma to Next.js, Performance Optimization, Lighthouse, Core Web Vitals, Stripe Integration, AI Chatbot, AI Assistant, AI Automation, AI Search, AI-Powered SaaS.