⭐️⭐️⭐️⭐️⭐️ Top 1% Expert-Vetted Web Developer on Upwork 📍 No short-term projects 📞 Kick-off with the team is mandatory 🧨 Available for a quick project start ★ Top-100 Service Provider by Clutch ★ $500M+ Raised by clients ★ 99+ International Awards ★ 15+ years of expertise (NOKIA, OPERA, OPPO, UDEMY, AUTH0, etc.) 👋 Hi, I'm Sergii! I'm a senior web developer, full stack developer Next.js specialist, and front end developer with 10+ years of experience building SaaS platforms, eCommerce products, AI applications, and custom web solutions. Over the years, I've helped launch 100+ products using React, React NextJS, Next.js, and modern JavaScript frameworks. My work combines technical architecture, front-end engineering, and product thinking to create fast, scalable applications that deliver measurable business results. 🏆 Why Clients Work With Me ✔ 100+ React, React Next, and Next.js projects delivered ✔ 50+ fully launched products across SaaS, AI, fintech, and eCommerce ✔ $500M+ raised by companies I've supported ✔ 20+ Upwork clients and long-term partnerships ✔ 30+ Shopify and Shopify Webflow projects completed ✔ Mobile and web products used by thousands of daily users ✔ Extensive experience as a front end developer React and front end Next specialist 🚀 Core Expertise 📌 Front-End Development As a front end developer, front end web developer, and front end designer, I've built interfaces for startups, enterprise products, and high-growth SaaS companies. Using React, React NextJS, Next.js, TypeScript, Tailwind, and modern UI frameworks, I create scalable applications focused on performance, maintainability, and user experience. My front-end work has helped companies reduce load times, improve conversion rates, and accelerate product delivery through reusable component systems and scalable architecture. 📌 React & Next.js Development I've delivered 100+ projects using React, React Next, and Next.js, including SaaS platforms, dashboards, marketplaces, AI tools, and enterprise applications. As a front end developer React specialist and full stack developer Next expert, I focus on building high-performance applications with clean architecture, SSR, SEO optimization, and long-term scalability. 📌 Mobile App Development Beyond web applications, I have extensive experience in mobile app development using React Native. I've helped teams launch mobile apps for healthcare, fintech, logistics, education, and SaaS businesses. As a mobile app developer, I work across the entire product lifecycle—from mobile app design and architecture to deployment and optimization. My experience includes React Native Mobile applications, cross-platform development, and React Native Full Stack solutions connected to modern APIs and cloud infrastructure. 📌 Shopify & Webflow Solutions I've worked on 30+ Shopify and Shopify Webflow projects, helping brands improve storefront performance, customer experience, and conversion rates. As a Shopify front end developer, I build custom themes, Shopify Hydrogen storefronts, and modern eCommerce experiences using Liquid, React, and headless architectures. I also collaborate closely with Webflow teams, helping businesses bridge design and development through scalable Webflow implementations and front-end optimization. 📌 AI & Python Integrations As a front end developer Python specialist, I've worked on AI-powered products featuring OpenAI integrations, vector search, chat interfaces, workflow automation, and custom dashboards. My experience includes Python APIs, automation workflows, AI assistants, and modern SaaS products powered by LLM technologies. 💻 Technology Stack React • React Next • React NextJS • Next.js • React Native • React Native Mobile • React Native Full Stack TypeScript • JavaScript • Node.js • NestJS • Express • Fastify Shopify • Shopify Webflow • Webflow • WordPress MongoDB • PostgreSQL • MySQL AWS • Google Cloud • Azure Tailwind • Storybook • GraphQL • Redux 🔥 What Clients Hire Me For ✔ Front End Developer React projects ✔ Full Stack Developer Next.js applications ✔ React Native Mobile App Development ✔ Shopify Front End Developer services ✔ Webflow and Shopify Webflow implementations ✔ Front End Designer and UI implementation ✔ Front End Developer Python integrations ✔ SaaS platforms and enterprise applications ✔ Mobile App Design and development ✔ Custom Web Development solutions 💎 Why Work With Me I combine the expertise of a web developer, front end developer, mobile app developer, and full stack developer into one delivery process. Clients work with me because I don't just build features—I help create products that scale, perform, and generate business value. Whether you need a front end developer React specialist, Shopify front end developer, React Native full stack engineer, mobile app developer, Webflow expert, or full stack developer Next.js partner, I'd be happy to discuss your project.

⭐️𝐒𝐞𝐧𝐢𝐨𝐫 𝐅𝐮𝐥𝐥 𝐒𝐭𝐚𝐜𝐤 𝐝𝐞𝐯 𝐰𝐡𝐨 𝐰𝐫𝐢𝐭𝐞𝐬 𝐜𝐨𝐝𝐞 𝐲𝐨𝐮𝐫 𝐟𝐮𝐭𝐮𝐫𝐞 𝐭𝐞𝐚𝐦 𝐰𝐨𝐧'𝐭 𝐜𝐮𝐫𝐬𝐞. 💡 130+ production-grade products delivered (SaaS, MVPs, AI systems, marketplaces) 💰 $16.5M+ revenue generated by client products 👥 157K+ active users powered by systems I built ⚡ 1M+ API requests/month at 99.9% uptime 🚀 MVP → production in 2–6 weeks, architected to scale from day one 🔥 WHAT I DO You're building a SaaS, MVP, or AI-powered product. You need a Full Stack Developer who can own React frontend and Node.js backend end-to-end, ship in weeks (not quarters), and write code your future team won't throw away. That's what I do. Early-Stage MVP, Productionizing a prototype, Scaling a Live SaaS Platform, or Legacy Codebase rebuild - I've built this on React, Next.js, Node.js, TypeScript, Supabase, PostgreSQL, AWS over 10+ years. 🔥 ROLES I TAKE ON (10+ YEARS EXPERIENCE) ✔ Full Stack Developer / Full Stack Engineer — 40+ end-to-end SaaS platforms (React + Node.js), 10+ years ✔ Frontend Developer / Front-End Developer — 30+ production UI builds, 10+ years ✔ React Developer / React.js / ReactJS Developer — scalable React apps since 2015, 10+ years ✔ Node.js / NodeJS Developer / Backend Developer — 25+ APIs, 1M+ req/month, 10+ years ✔ Vue.js Developer / Nuxt.js Developer — 8+ Vue projects, 8+ years ✔ Next.js Developer / NextJS Developer — 15+ SSR/SSG SaaS platforms, 7+ years ✔ TypeScript Developer / JavaScript Developer — 50+ typed and untyped JS codebases, 10+ years ✔ SaaS Developer / Web Application Developer / Web App Developer — MVP to scale, 10+ years ✔ Lead Frontend Engineer / Senior Full Stack Engineer — team leadership on 18+ projects 🔥 INDUSTRIES I SERVE ⚖️ For LegalTech founders — 6+ Case Management Systems, Document Workflows, Client Portals, Compliance SaaS 🏥 For Healthcare & MedTech — 8+ Patient Platforms, Telehealth, HIPAA-Compliant data, Clinic Management SaaS 📦 For Logistics & supply chain — 5+ Logistics Platforms, real-time tracking (sea/air/truck), Project44, INTTRA, EDI 🛒 For Marketplace & e-commerce — 15+ Multi-Vendor Marketplaces, B2B & Two-Sided Marketplace, Stripe, bidding, complex search 🤖 For AI startups — 12+ AI-Powered products: OpenAI / Claude API / LLM, RAG Chatbots, AI Agent Platforms, vector DBs, FastAPI, browser extensions 📝 For No-code & enterprise SaaS — 10+ Form Builders, Admin Dashboards, Internal Tools, Microservices, Multi-tenant 🌐 For Media, AdTech & publishing — 6+ Publisher Platforms, CMS, payment gateways, Analytics Dashboards 🏠 For Real estate & PropTech — Property Listings, Bidding & Auction systems, Agent Dashboards 💰 For FinTech founders — Stripe Connect, subscription billing, multi-currency, KYC, Fintech MVP 📚 For EdTech — course delivery, student dashboards, progress tracking, live sessions 🔥 RESULTS I DELIVER ✔ MVP → production in 2–6 weeks, 35% fewer bugs, 5–8 weeks shorter delivery cycle ✔ Frontend: LCP under 1.5s, Lighthouse 90+, bundle reduced 40%, 18–27% engagement uplift ✔ Backend: 1M+ API requests/month, 99.9% uptime, 40–60% lower latency ✔ Database: 3–5x faster response, 70% less DB load; 90% faster workflows, 65% fewer back-office actions ✔ +30% conversion on React / Next.js apps; 15–22% better marketplace lead quality ✔ 15,000+ shipment operations/month, 2,423+ completed orders, 30,000+ healthcare users ✔ 20+ SaaS MVPs launched, 47% fewer bugs in legacy modernization 🔥 HOW I WORK I think like a product engineer, not a code-monkey. Before writing a line, I align on the business outcome — who the user is, what they pay for, where the product needs to be in 6 months. Then I ship in weekly demos and stay available on Slack / Telegram for fast turnaround. Typical cycle: 1️⃣ Discovery & scoping (2–3 days) — define MVP boundary 2️⃣ Architecture — clean foundations, scalable schema, right stack 3️⃣ Weekly sprints with demos — progress every week 4️⃣ Production launch — CI/CD, monitoring, error tracking 5️⃣ Post-launch support — most clients keep me on 🔥 TECH STACK Frontend: React.js, ReactJS, React Hooks, Next.js, NextJS, Vue.js, Nuxt.js, TypeScript, Redux, Zustand, Tailwind CSS, shadcn/ui Backend: Node.js, NodeJS, Express.js, NestJS, Python, FastAPI, REST, GraphQL, WebSockets Database: PostgreSQL, Supabase, MongoDB, MySQL, Redis, Prisma Supabase: Auth, Row-Level Security, Edge Functions, Realtime, Storage AWS: Lambda, S3, RDS, EC2, CloudFront, API Gateway, SQS, SNS, Cognito, ECS Other cloud: Firebase, Vercel, Netlify, Cloudflare AI / ML: OpenAI API, Claude API, LangChain, RAG, RAG Chatbot, AI Agent, pgvector, Computer Vision Payments: Stripe Subscriptions, Stripe Connect, Stripe Checkout, Stripe Billing, PayPal Integrations: Twilio, SendGrid, Resend, Slack API, Telegram Bot API, EDI, Project44, Mobile: React Native, React Native Expo, iOS / Android DevOps: Docker, GitHub Actions, CI/CD, Sentry 🚀 Building a SaaS, MVP, marketplace, or AI-powered product? Click "Invite" or "Hire" and send the brief.

As a React Developer and Full Stack Developer I build custom Web Application products for B2B clients, from interface to backend. Most of my work is Full Stack Developer React Node delivery, where a React frontend and a Node.js backend support one business workflow end to end. As a Node.js Developer I own the REST API logic, authentication, roles and permissions, and the data layer behind each product. My focus is practical Web Application Development that ships, scales, and stays maintainable, with clean API Integration at the core. Across 14+ years and 130+ completed projects I have built 60+ SaaS, CRM and dashboard products, 40+ admin panels and client portals, and 200+ REST API integrations. As a React Developer and Full Stack Developer with experience leading development teams of up to 6, I have shipped for 50+ EU and US B2B clients across SaaS platforms, CRM systems, marketplaces, booking websites and API Integration projects. As a React Developer I build Web Application interfaces with React.js, Next.js, TypeScript and Responsive UI , wired to live data through API Integration . As a React Frontend Developer and Frontend Developer I deliver usable, fast interfaces — data tables, filters, admin panels and client portals. On the backend side, as a Node.js Developer and Backend Developer I build the REST API layer, ExpressJS services, authentication, roles and permissions, payment flows and CRM integrations. Many clients come to me as a Node.js Developer when a frontend already exists but the API, the data model and the business logic need to be done right. As a Backend Developer I keep the Node.js layer predictable and documented, and as a Node.js Developer I handle the API Integration between third-party services, the database and the frontend. A typical Full Stack Developer React Node project for me looks like this: a SaaS platform or internal business tool with a React frontend, a Node.js backend, a structured database and an admin workflow for the team behind it. On every Full Stack Developer React Node build I design the database structure, the REST API , the dashboards and the permissions model so the product holds up as it grows. This Full Stack Developer React Node approach keeps frontend and backend in one system. Hiring one Full Stack Developer React Node engineer also keeps the React Developer and Node.js Developer decisions consistent across the whole build. I also work as a Directus Developer and Headless CMS Developer . On 20+ content-driven and data-heavy products I use Directus CMS or Strapi as a headless backend, which gives clients a clean admin panel and an API-ready foundation. As a Directus Developer I model the data, set roles and permissions, and connect a React frontend through REST API ; as a Strapi Developer I do the same on Strapi. Headless CMS work with Directus CMS pairs naturally with my React Developer and Node.js Developer delivery. Stack I use daily: React, React.js, Next.js, Node.js, TypeScript and JavaScript on the application side; ExpressJS, REST API and API Integration on the service side; SQL, MySQL, MongoDB, Firebase and Supabase for data; Directus CMS and Strapi for headless content. Authentication, roles and permissions, payment flows, dashboards, data tables, filters and admin workflows are standard parts of how I deliver Web Application Development . How I work on a Full Stack Developer React Node project: discovery and scope first, then architecture and backlog, design where needed, development in sprints, QA on staging, production release, and support after launch. As a Web Developer with 14+ years behind me, my main promise is delivery predictability — clear scope and no surprises. As a JavaScript Developer I write code the next developer can actually read and extend. Typical projects clients hire me for: SaaS platform development, CRM systems, admin panels, marketplaces, booking websites, lead generation websites, dashboards, client portals, internal business tools, e-commerce platforms and API-based Web Application work with workflow automation and business automation. Clients also find me under related searches that match my real stack. On the React side: React Native Developer , React Native App Developer , React Next.js Developer , React Developer Firebase , and Full Stack Developer Supabase React . On the full stack side: Python Full Stack Developer , Full Stack Developer AI , Full Stack Developer Shopify , Full Stack React , Full Stack Node.js React and Node.js React . On the backend: Node.js Backend Developer and Back End Developer Node.js . I also fit Front-End Developer Full-Stack , Python Developer , WordPress Developer , Mobile App Developer and Senior Full Stack Developer . If you need a React Developer , a Full Stack Developer React Node engineer, or a Node.js Developer for a serious product, I can take it from architecture through release and support. Let's talk about your product and what it needs to do. Let's get in touch!

⭐️⭐️⭐️⭐️⭐️ TOP RATED PLUS | Front End Developer | React Developer | Full Stack Developer | Next.js Developer — building scalable, production-grade products used by thousands of users 🚀 🔥 49 COMPLETED JOBS WITH ZERO NEGATIVE FEEDBACK ⭐️ Consistent 5-STAR REVIEWS & LONG-TERM CLIENT PARTNERSHIPS 💼 $200K+ earned on Upwork | ⏱ 8,000+ hours delivered | 🏆 100% Job Success Rate 🌍 40+ products shipped across 18+ countries | 🏅 15+ long-term client partnerships Building a serious product takes more than a polished UI — it takes a Full Stack Developer who understands architecture, scalability, and business impact. I'm a senior Front End Developer and Full Stack Developer with 9+ years building high-performance web apps, SaaS platforms, landing pages, and mobile apps for startups and growth-stage companies with React, Next.js, and Node.js. I keep frontend and backend tightly integrated so every decision serves the business. 📊 Impact & Metrics Products I've shipped serve 10K–100K+ monthly actives and handle 5M+ API requests/month. As a Front End Developer and React Developer I've cut load times 40–60%, lifted conversions 20–35%, and dropped bounce rates 25%+. Recent work: organic traffic +62%, TTI 2–3x faster, and a dashboard rebuild that grew weekly actives from 4K to 18K (+350%) in 4 months. 🏗 Architecture & Scalable Systems As a React Developer I design scalable component systems with Redux or Zustand; with Next.js I build hybrid rendering — SSR, SSG, ISR, API routes — tuned for performance and SEO. As a Full Stack Developer I work in Node.js, ExpressJS, and Python (Django, FastAPI), building REST APIs across PostgreSQL, MySQL, MongoDB, and Supabase, with WebSockets, Docker, and CI/CD on AWS or Vercel cutting release times 50%+. Modular patterns reduce technical debt and bug rates 30–40%. 🤖 AI Development & Intelligent Systems I build production-ready AI apps and agents with the OpenAI API and Claude, connecting LLMs to real product needs, not demos. As a Full Stack Developer and React Developer, I ship conversational interfaces, multi-step reasoning pipelines, ML features inside existing platforms, and AI-powered dashboards that save teams 15–25 hours/week. 📱 Mobile App Development Beyond the web, I build cross-platform apps with React Native for Android and iOS, sharing logic with the web codebase to cut delivery time up to 40%. As a Front End Developer who treats mobile as a first-class surface, I've shipped apps holding 4.5★+ store ratings. 🎨 Design-to-Code & Website Builds I turn Figma and Framer designs into pixel-perfect, responsive interfaces with Tailwind CSS and SCSS — landing pages, full websites, or redesigns, always polished and fast. As a Front End Developer I consistently hit Lighthouse 95+ and median LCP under 1.8s. 📈 Business-Oriented Engineering As a React Developer I've refactored unstable React codebases into maintainable systems, shipped Next.js platforms that grew organic acquisition, built Stripe subscription and marketplace flows, and handled API integration, cutting infra overhead 20–30%. One Full Stack Developer engagement took a signup funnel from 90 to 240/month (+165%) while halving server costs. ⚡ Performance & Optimization I treat Core Web Vitals like LCP and TTI as real product metrics, getting them 2–3x faster through code splitting, lazy loading, caching, and SSR/ISR/static rendering. As a Front End Developer obsessed with speed, I've taken pages from 6s+ to sub-2s, lifting conversion +38% and cutting bounce 25%+. 🔧 Primary Stack Frontend: React.js, Next.js, TypeScript, Redux, Zustand, Tailwind CSS, SCSS, Framer. Backend: Node.js, ExpressJS, Python (Django, FastAPI), REST, GraphQL, WebSockets. AI: OpenAI API, Claude, custom ML. Mobile: React Native, native Android. Infra: AWS, Vercel, Docker, CI/CD, PostgreSQL, MySQL, MongoDB, Redis, Supabase. Need a React Developer for a complex SPA or a Full Stack Developer to own the whole product? The stack flexes to fit. 💡 Data-Backed Results at a Glance ✅ 60% faster load times via Next.js rendering & caching ✅ 35% increase in conversion rates through funnel-focused Front End Developer work ✅ 350% growth in active users on a React Developer dashboard rebuild ✅ 62% lift in organic traffic via SEO-optimized SSR/SSG ✅ 50% shorter release cycles after CI/CD automation ✅ 40% reduction in mobile delivery time through shared React Native logic ✅ 30% drop in technical debt and bugs via modular components ✅ 25% lower bounce rates after Core Web Vitals work ✅ 165% more signups on a Stripe SaaS funnel rebuild ✅ 95+ Lighthouse scores with sub-1.8s LCP 🤝 How I Work I stay product-focused, build clean, scalable architecture from day one, and iterate fast without piling up technical debt. As a Front End Developer and Full Stack Developer who's partnered with 40+ founders, CTOs, and product teams, I prefer long-term partnerships over one-off gigs. Looking for a React Developer who thinks in products, not tickets? Let's talk.

🚀🚀🚀 I help businesses build fast, user-friendly, and SEO-optimized websites that convert visitors into clients. I combine clean front end development with flexible WordPress solutions to deliver measurable business results. Tailored Websites That Help Your Business dive, thrive, and scale 🚀🚀🚀 🏆🏆🏆 Top-Rated Plus WordPress Developer, Front End Developer, Front End Web Developer, WordPress Elementor developer. I have 7+ years of experience in Front End Development. I have 6+ years of experience as a WordPress Full Stack Developer. I’ve completed 150+ projects, maintain a 100% Job Success Score, and have logged 3700+ hours on Upwork. As a WordPress Developer and Website Designer aand WordPress UI UX developer, I create custom WordPress website design solutions using WordPress Elementor, Avada, and other modern builders. I also work with Shopify as a Shopify Developer, delivering scalable eCommerce solutions. My background in web design allows me to bridge the gap between design and development for a creating pixel-perfect websites. I react fast to the client's requirements. I specialize in building SEO-optimized, responsive, and high-performing WordPress websites with clean, maintainable, and scalable code. Every project is crafted to ensure excellent UX UI, strong performance, and long-term growth - helping users dive into content and thrive, following conversion-focused principles inspired by Thrive Theme philosophy. I’ve worked as a Front End Web Developer and Full Stack Web Developer (PHP) on large-scale projects, collaborating closely with backend developers, designers, and project managers. My experience also includes working as a React Developer, building interactive and dynamic interfaces using React and modern JavaScript frameworks. As a WordPress back-end developer, I develop custom functionality, plugins, and integrations using PHP, delivering scalable and efficient solutions tailored to each project's needs. Projects I work with: ✔️ Landing pages ✔️ WordPress website development ✔️ WordPress website design and redesign ✔️ Corporate websites ✔️ Front end projects ✔️ eCommerce websites ✔️ B2B and B2C projects Technologies & tools: ✔️ HTML, HTML5, CSS, CSS3, Tailwind CSS, SASS ✔️ JavaScript, Vanilla.js, jQuery, Bootstrap, Canvas ✔️ React, React.js ✔️ PHP, Laravel, API integration ✔️ MySQL, SQL ✔️ WordPress (ACF, Elementor, Bakery Builder, Bricks Builder, Brizy, WooCommerce, BuddyPress, Gutenberg, LearnDash, Divi, Avada) ✔️ SEO optimization ✔️ Shopify ✔️ Parallax, motion animations ✔️ Dashboard development ✔️ Sketch, Figma, Zeplin, PSD, Adobe XD, Adobe InDesign, Adobe Photoshop ✔️ Responsive / Cross-browser / Cross-platform development ✔️ Pixel-perfect implementation ✔️ Git / Bitbucket 🏆 Why my work stands out 7+ years of experience in WordPress and front-end development 150+ completed projects for businesses, startups, and agencies Clean, scalable builds using ACF, Elementor, and custom solutions Focus on performance, SEO structure, and Core Web Vitals Experience with WooCommerce, Stripe integrations, and dynamic content Structured approach that makes websites easy to manage and extend Responsive builds optimized for all devices and screen sizes Strong focus on UX and conversion-driven layouts Projects built with a structured approach typically achieve: • up to 40 - 60% faster load times after optimization • 20 - 40% improvement in user engagement (time on page, interactions) • cleaner UX and structure leading to better conversion flow • scalable architecture that reduces future development time by 30 - 50% I’m a detail-oriented Web Developer with a strong focus on architecture, performance, and scalability. I provide clear daily communication, regular updates, and can commit 40+ hours per week. If you’re looking for a reliable WordPress Developer, Front End Developer, or Full Stack Web Developer who can design and build a website that truly helps your business thrive - let’s discuss your project.

AI-Leveraged Delivery — ship 2× faster ⚡ Most developers say they're "fast." Then the staging environment shows up in week six. I do it differently — and I can show you the receipts. 🧾 ◆ 100% Job Success Score | Top Rated Plus | Full Stack Developer | React Next.js | Front End Developer ◆ I've been doing Software Development for 8+ years. In that time I've worked on everything from quick Landing Pages to multi-year SaaS platforms - and the thing that's stayed consistent is that clients get a working product, not a list of reasons why it's late. I work as a Full Stack Developer and Front End Developer, which means I'm comfortable owning the whole thing. React and Next.js are where I spend most of my time, but the stack goes deeper: Node.js, Python, PHP, Laravel, TypeScript, MongoDB, MySQL, PostgreSQL, SQL - whatever the project actually needs. I don't have a favourite technology. I have a favourite outcome: software that ships and works. ◆ FRONT-END DEVELOPMENT Front-End Development is my home base. I work with React, Next.js, Vue.js, Angular, JavaScript, TypeScript, HTML, HTML5, CSS, CSS 3, Bootstrap, jQuery, Redux, and Workbox.js for PWA builds. Web Design and Responsive Design aren't an afterthought - I work from Figma and Adobe Photoshop and care about how things look and feel across every device. PSD to HTML conversion, Front-End Development Framework setup, pixel-accurate implementation - all part of the job. ◆ FULL-STACK & BACK-END As a Full Stack Developer I connect the front end to a real backend: Node.js, Python, PHP, Laravel, NestJS, REST API, API Integration, SQL, MySQL, MongoDB, Database Architecture, Git, CI/CD. I've set up auth systems, payment flows via Stripe, third-party API Integration, and backend logic that doesn't fall over when traffic spikes. ◆ WHAT I BUILD ◆ SaaS platforms and Web Applications - React, Next.js, TypeScript, Redux, Tailwind, clean Web Design, fast load times, and Responsive Design that holds up on every screen ◆ AI-powered products - RAG pipelines, chatbots, OpenAI and Claude API Integration, document processing tools, pgvector retrieval ◆ E-commerce and WordPress - WooCommerce, custom themes and plugins, PSD to HTML, Web Development that converts ◆ Landing Pages and marketing sites - HTML5, CSS 3, Bootstrap, jQuery, Responsive Design, conversion-focused Web Design built for speed ◆ React Native mobile apps - cross-platform iOS and Android, shared codebase, App Store and Google Play ◆ Web Developer work across the full stack - API, Database Architecture, Laravel and PHP backends, Node.js services ◆ INDUSTRIES I've shipped projects across fintech and payments, healthcare and medical platforms, e-commerce and retail, EdTech, real estate, logistics and delivery, SaaS and B2B tools, marketplaces, social platforms, media and streaming, legal tech, travel and booking, fitness and wellness, and non-profit. Most verticals at this point. ◆ HOW I WORK I communicate early and directly. If scope is unclear I'll say so before we start, not after week four. If an approach won't work I'll tell you - and offer an alternative. Staging live in week one, weekly updates, clean code your next developer won't hate. ◆ RELATED EXPERTISE Full Stack Developer: web developer, react developer, wordpress developer, mobile app developer React Next.js: nestjs, workbox.js, web developer, front end developer Front End Developer: web developer, full stack developer, react developer, react ◆ READY TO START ASAP

👋 Need a Front end Developer React who can take ownership of your product and deliver polished, production ready experiences? I'm a Top Rated Front end Developer React with 12+ years of commercial experience building SaaS platforms, dashboards, customer portals, and modern web applications. With $30K+ earned, 1100+ hours worked, and a 100% Job Success Score, I focus on creating scalable solutions that combine excellent user experience with maintainable architecture. As a React Full Stack Developer, I've helped clients across 15+ countries transform ideas into successful products and scalable platforms. I've contributed to applications ranging from startup MVPs to products serving more than 5 million end-users worldwide. I've built mobile applications used by millions, SaaS products powering growing businesses, and streaming platforms delivering video and audio experiences in real time across multiple markets. As a React Full Stack Developer and Full Stack Developer React Node.js, I contribute across the entire product lifecycle from frontend architecture and user experience to backend integrations and feature delivery. My experience as a Full Stack Developer React Node.js allows me to support complex business requirements while building reliable systems designed for growth. 🏆 Why Clients Work With Me • Top Rated with 100% Job Success • 12+ years of commercial development experience • $30K+ earned and 1100+ hours on Upwork • Product ownership • Scalable solutions • Reliable delivery As a React Full Stack Developer, I focus on delivering practical solutions that balance technical excellence with real business objectives. 🚀 Services 📌 Front End Development As a Front end Developer React Node.js, I build responsive, highperformance applications using React, Next.js, TypeScript, modern frontend practices. • Dashboards & Admin Panels • Customer Portals • Internal Tools • Responsive Web Applications • Reusable UI Systems • Frontend Architecture & Refactoring 📌 Full Stack Product Development As a React Full Stack Developer and Full Stack Developer React Node.js, I work with growing teams to build and evolve SaaS products, MVPs, business applications. • SaaS Platforms • MVP Development • Feature Development • Product Modernization • Technical Discovery • End to End Implementation 📌 Backend Integrations As a Full Stack Developer React and Full Stack Developer React Node.js, I integrate backend services that support business workflows. • REST API • GraphQL • Authentication & Authorization • Payment Integrations • Third Party Services 📌 Product Growth As a Full Stack Developer React, I support products beyond launch through performance improvements, architecture enhancements, and ongoing development. 🔧 Technologies React • Next.js • TypeScript • JavaScript • Node.js • Redux • Tailwind CSS • REST API • • Supabase • Firebase • PostgreSQL • Docker • Stripe • AWS As a React Full Stack Developer and Full Stack Developer React Node.js, I build applications using clean architecture, reusable code patterns, and development practices designed to support long-term business growth. 💼 Selected Experience 🏥 Healthcare Platform Worked on healthcare applications focused on improving operational workflows and user experience. As a Front end Developer React, I developed responsive interfaces, integrated APIs, optimized user journeys, and delivered features supporting both medical staff and end users. 🚚 Cargo & Logistics Platform As a React Full Stack Developer and Full Stack Developer React Node.js, I built dashboards, shipment management interfaces, workflow solutions, and integrations supporting logistics operations and transportation processes. 👥 Recruitment & Hiring Platform As a Full Stack Developer React, I developed candidate management dashboards, search and filtering systems, workflow features, and integrations supporting recruitment and hiring processes. 📌 Additional Expertise As a Front end Developer React, I collaborate closely with founders, product managers, and stakeholders to transform business requirements into intuitive user experiences and scalable technical solutions. As a React Full Stack Developer I have experience working with existing codebases as well as building products from the ground up. My background as a Full Stack Developer React Node.js includes implementing secure authentication flows, integrating payment systems, optimizing application performance, and supporting products through multiple stages of growth. 📌 Industries Healthcare, logistics, recruitment, booking platforms, E-commerce As a Full Stack Developer React Node.js, I enjoy partnering with ambitious teams building products designed to scale. 💡 What Clients Value Clients value my ability to contribute as a Front end Developer React while understanding the broader product vision and delivering results as a Full Stack Developer React. If you need a Front end Developer React Node.js, let's connect.

E-commerce, marketplace, and SaaS platforms that drive real growth. 🏆 100,000+ active users reached on a single platform within 6 months 📈 20%+ conversion growth through data-driven UI decisions 💰 €10M+ annual revenue supported across e-commerce platform 🚀 Figma design → production-ready frontend in days, not weeks Senior Front-End Developer and Full Stack Developer with 7+ years of hands-on experience building products from the first commit to full production scale. I work primarily as a React Developer and Next.js Developer, crafting fast, SEO-friendly, and accessible interfaces with React.js, Next.js, TypeScript, and Redux. On the backend side, I connect everything using Node.js, Express.js, NestJS, and Firebase. My focus is always the same: a product that works, performs, and grows. 𝐏𝐫𝐨𝐝𝐮𝐜𝐭𝐬 𝐈'𝐯𝐞 𝐛𝐮𝐢𝐥𝐭: European E-commerce Platform - Clothing Multi-store. Senior Front-End Developer on one of Europe's largest streetwear stores with €10M+ annual revenue. Built multi-store, multi-language, multi-currency architecture with full catalog management, promotions engine, and logistics integrations. Helped scale the platform into new European markets and establish it as the #1 streetwear destination online. Healthcare Marketplace - React Developer on a platform connecting clients with licensed psychologists for online therapy. Built therapist matching, session booking, wallet system, promo codes, and gift certificates. Result: 100,000+ active users within 6 months, consistently praised for UX quality. Travel Marketplace - Full Stack Developer and React Native Developer on a web and mobile app connecting charter pilots with travelers across US–Bahamas routes. Delivered split payments, Smart Check-In, passenger invitations, and scheduling system. Opened new revenue streams for pilots, streamlined the entire booking experience. E-commerce Platform - As a React Developer and Node.js Developer, I built a full-featured furniture store with advanced catalog filtering, product customization, wishlist, and comparison. Developed a custom CMS and CRM for independent business operations. Integrated AI-powered product recommendations and technical SEO, resulting in top search rankings. Result: 100,000+ monthly users 𝐂𝐨𝐫𝐞 𝐄𝐱𝐩𝐞𝐫𝐭𝐢𝐬𝐞: React.js and Next.js frontend development TypeScript, Redux, and state architecture React Native mobile development (iOS & Android) Full stack development with Node.js, NestJS, Express.js SaaS MVP → production delivery E-commerce and marketplace platforms (B2B / B2C / P2P) Figma to React conversion, pixel-perfect implementation Payment integrations (Stripe, PayPal) AI-powered features (OpenAI, GPT-4, automation) Performance optimization and Core Web Vitals REST API and third-party service integrations Firebase, MongoDB, real-time systems 𝐓𝐞𝐜𝐡 𝐬𝐭𝐚𝐜𝐤: Frontend: React.js, Next.js, TypeScript, JavaScript, Redux Mobile: React Native, Expo Backend: Node.js, Express.js, NestJS Database: MongoDB, Firebase, PostgreSQL Styling: Tailwind CSS, Material UI, Styled-components, Bootstrap, HTML5, CSS3 Tools: Git, CI/CD, Webpack, Vite Integrations: Stripe, PayPal, OpenAI, GPT-4, REST APIs, GraphQL Design: Figma, Zeplin, Adobe Photoshop, Illustrator 𝐖𝐡𝐲 𝐡𝐢𝐫𝐞 𝐦𝐞: ✔ Pixel-perfect implementation from any Figma file ✔ SEO-optimized, fast-loading Next.js applications ✔ Clean, maintainable component architecture built to scale ✔ Real-time features, complex API integrations, payment flows ✔ Daily updates, honest timelines, zero surprises ✔ Fluent English - comfortable across US and EU time zones 𝐈'𝐯𝐞 𝐰𝐨𝐫𝐤𝐞𝐝 𝐚𝐜𝐫𝐨𝐬𝐬 𝐫𝐨𝐥𝐞𝐬: React, React Developer, Frontend React Developer, Front-End, Next.js Developer, Full Stack Developer, Marketplace, E-commerce, React Native, React Node, React Native Developer, Mobile Developer, Web App Developer, Mobile App Developer, WordPress, Tailwind, Web Developer, SaaS Developer, E-commerce Developer, Nurpais, Marketplace Developer, AI Frontend Developer. Have a project in mind? Reach out - I'll respond quickly with the right questions to turn your idea into reality.

👋 Hi, I'm Julia from Koitechs - Top Rated Plus Upwork team focused on React, Next.js, Node.js, React Native, TypeScript, Supabase, PostgreSQL, and AI product development. My main goal is save up to 40% of our budget to get a market-ready, stable and scalable product. I help companies hire in-house, CTO-approved engineers who join fast, take ownership, and deliver production-ready software. ✅ 9+ years in software development ✅ 155+ web and mobile projects delivered ✅ 20,500+ Upwork hours in React / Next.js / Node.js / React Native ✅ 75% repeat clients ✅ Engineer matching in 24 hours or less ✅ 2-week trial period ✅ 35+ in-house engineers ✅ 40+ MVPs released ✅ Products supported by our team include platforms with 5M+ daily users 🚀 React / Next.js / Full Stack We build SaaS platforms, marketplaces, dashboards, admin panels, CRMs, AI products, and scalable web apps using React, Next.js, Node.js, TypeScript, Supabase, PostgreSQL, Firebase, MongoDB, REST API, GraphQL, Stripe, OAuth, WebSockets, AWS, Vercel, and Docker. Our team is a strong fit if you need a react developer , web developer , full stack developer , nextjs developer, mern developer, or backend engineer. We help with MVP development, legacy code takeover, architecture modernization, Core Web Vitals, API integrations, payments, auth, subscriptions, user roles, and production launch. 📱 React Native / Mobile We build and support iOS and Android apps using React Native, Expo, Firebase, Supabase, Node.js, and API-driven architecture. We can help if you need a react native developer , mobile app developer, iOS / Android support, app takeover, mobile maintenance, push notifications, App Store / Google Play releases, payments, or backend integrations. We also support mixed mobile environments with flutter developer , android developer , backend developer, AI developer, or web developer. 🤖 AI SaaS / AI App Development We build AI-powered products connected to real business workflows. Experience: AI SaaS, AI MVPs, AI chatbot development, AI agent development, OpenAI API, Claude API, LLM prompt engineering, RAG, automation, web scraping, AI model integration, copilots, and AI workflow validation. AI stack: OpenAI API, Claude API, LLMs, RAG, AI Agent Development, AI Chatbot, Generative AI, Python, FastAPI, Supabase, PostgreSQL, pgvector, automation, data analysis, web scraping. 🧩 Mixed-Stack Support Our core focus is React, Next.js, Node.js, React Native, TypeScript, Supabase, and AI. We also support products involving wordpress , vue , angular , python developer , scala developer , flutter developer , android developer , mern , and other web/mobile technologies. 🏆 Industries 📦 Logistics - 5+ projects: tracking, shipment dashboards, carrier/shipper workflows, maps, route visibility. 🏥 HealthTech -4+ projects: medical booking, clinic platforms, patient flows, admin systems. 🛒 Marketplaces & E-commerce - 15+ projects: multi-vendor products, Stripe, subscriptions, bidding, complex search. 🏠 PropTech / Real Estate -5+ projects: listings, booking flows, agent dashboards, rental platforms. 🤖 AI Startups - 25+ AI products/features: AI SaaS, chatbots, agents, copilots, OpenAI / Claude integrations. 💰 FinTech - 3+ projects: Stripe Connect, billing, payment flows, invoicing. 🎮 Gaming - 5+ projects, including 2 major global gaming brands: dashboards, analytics, real-time interactions. 📚 EdTech - 5+ projects: student dashboards, progress tracking, content platforms. 📣 MarTech - 1 global market-leading project: dashboards, analytics, segmentation, workflows. ⚽ SportsTech - 10+ projects: live data, dashboards, events, rankings, stats, mobile apps. 📌 How We Work 1️⃣ Discovery & technical planning 2️⃣ Engineer matching within 24h 3️⃣ 2-week trial period 4️⃣ Weekly demos and reports 5️⃣ CTO-approved delivery with code review and QA 6️⃣ Long-term support after launch 🚀 Building a SaaS, MVP, marketplace, React app, Next.js platform, React Native app, AI product, or mixed-stack web/mobile platform? Click “Invite” or “Hire” - I’ll help you clear the estimate or discovery phase within 24 hours or less.

Hi, I'm Dmytro. I'm a Front End developer with more than 8 years of experience building web and mobile applications for startups, product companies, and growing businesses. As a Front End developer, I've worked on MVPs, SaaS platforms, e-commerce products, internal business tools, and customer-facing applications used by thousands of users. My primary focus as a Front End developer is creating fast, responsive, and user-friendly applications using modern JavaScript technologies. I enjoy transforming complex requirements into clean, maintainable solutions that provide real value to users and businesses. Throughout my career as a Front End developer, I've worked closely with designers, product managers, backend engineers, and business stakeholders to deliver products that are both technically solid and enjoyable to use. I believe a successful Front End developer should understand not only the code but also the goals behind the product. Technologies I work with As a Front End developer, my main stack includes: React Next.js TypeScript JavaScript React Native Angular Vue.js HTML5 CSS3 Tailwind CSS Material UI (MUI) SCSS Webpack Vite Node.js Over the years, I've helped companies hire a reliable Front End developer who can contribute quickly, improve existing codebases, and build new features with confidence. What I can help with As a Front End developer, I can help with: Building modern web applications from scratch Developing scalable React and Next.js applications Creating reusable component libraries Design system implementation Responsive and mobile-first development Performance optimization Server-Side Rendering (SSR) Progressive Web Apps (PWA) API integration Frontend architecture React Native mobile applications Refactoring legacy projects Bug fixing and maintenance Many clients choose me as a Front End developer because I can quickly understand business requirements and translate them into practical solutions. When companies need a Front End developer who can take ownership of a feature from planning to production, I can provide that support. I've worked as a Front End developer on both small startup projects and large-scale applications. My experience as a Front End developer allows me to adapt to different team structures, coding standards, and development processes. Although my primary role is a Front End developer, I also have experience with backend development. This broader perspective helps me become a more effective Front End developer because I understand how frontend systems interact with APIs, databases, and cloud infrastructure. I've worked with: PostgreSQL MongoDB MySQL Firebase Firestore Supabase AWS Node.js Python PHP This experience allows me to work effectively with backend teams and contribute as a Front End developer who understands the complete product lifecycle. How I work I believe a great Front End developer should focus on more than writing code. A Front End developer should understand user experience, accessibility, performance, maintainability, and business objectives. As a Front End developer, I value clear communication, ownership, and attention to detail. Every Front End developer should be able to balance technical excellence with practical business needs, and that's the approach I bring to every project. I've also contributed as a Front End developer in areas such as: Code reviews Technical planning Frontend architecture Git workflows CI/CD pipelines Agile development Team collaboration Mentoring junior developers Whether you need a Front End developer for a short-term project, a Front End developer for long-term collaboration, or a Front End developer to strengthen your current engineering team, I can help. My goal as a Front End developer is to build products that users enjoy using and that businesses can confidently grow over time. Companies often look for a Front End developer who can join an existing team and become productive quickly. Others need a Front End developer to help launch a new product or modernize an existing application. In both cases, I focus on delivering reliable, maintainable, and scalable solutions. If you're looking for a Front End developer with strong React expertise, modern frontend experience, and a practical approach to product development, I'd be happy to discuss your project. Best regards, Dmytro