Oleg Z.

💡 Delivering Scalable Products with React & Full Stack Expertise 💡 📅 10+ years of experience 📦 60+ successfully delivered projects 💰 $10M+ generated for clients 👥 Products with 24,000+ active users I’m a Senior Full Stack React Developer with over 10 years of experience building reliable, scalable web applications. As a React Developer, Next.js Developer, and Node.js Developer, I’ve delivered 60+ projects across SaaS, marketplaces, healthcare, fintech, and real estate. As a React Node.js Developer and Full Stack Developer, I’ve launched 50+ production-grade systems with 99.9% uptime, supporting thousands of users and millions of monthly requests. My work as a Full Stack Developer has helped clients generate over $10M and accelerate product delivery by 30–40%. 🧩 Full Stack React, MERN Stack & Backend Systems I work as a Full Stack Developer, Full Stack React Developer, and React Node.js Developer, building applications with React.js, Frontend React, Next.js (Nextjs), and scalable backend architectures. I specialize in the MERN stack, delivering complete end-to-end solutions as a Full Stack Developer and React Node.js Developer. My experience with the MERN stack includes multiple production systems powered by MongoDB, Express, React.js, and Node.js. As a Full Stack Developer and React Node.js Developer, I focus on: ⚙️ Improving performance (LCP/TTI) by 2–3x 📊 Increasing conversions by 30–35% 📈 Scaling applications to 120K+ users 🛠 Building stable and maintainable backend systems My background with the MERN stack, React.js, and backend architecture allows me to consistently deliver scalable products as a Full Stack Developer. 🗄 Backend, Databases & Supabase As a Full Stack Developer and React Node.js Developer, I design and build APIs, dashboards, and real-time systems. I work with SQL, PostgreSQL, MySQL, and MongoDB, creating optimized schemas and high-performance data layers. My experience with MongoDB includes building high-load systems within the MERN stack ecosystem. I also use Supabase / Postgres to build modern backend solutions with authentication, RLS, edge functions, and real-time features. 🧠 Built systems using MongoDB, PostgreSQL, and MySQL 🔄 Processed 50K–300K events/day using Supabase 💸 Reduced backend costs by up to 50% with Supabase 🚀 Improved delivery speed by 40% As a Full Stack Developer and React Node.js Developer, I ensure backend scalability, reliability, and long-term maintainability. 🎨 Frontend React & Next.js With 10+ years as a React Developer, React.js Developer, and Frontend React Developer, I build fast, user-focused interfaces using React.js and Next.js (Nextjs). As a Full Stack Developer and React Node.js Developer, I seamlessly connect frontend applications with backend services. ⚡ Improved load times by 50% 📉 Reduced bounce rates by 25–30% 📈 Increased user engagement by 40–45% 📱 React Native & Cross-Platform Development As a React Native Developer, alongside my work as a Full Stack Developer and React Node.js Developer, I build mobile apps integrated with scalable backend systems powered by MongoDB, Supabase, Firebase, and SQL. 📲 12+ mobile apps delivered 👤 130K+ active users supported 💳 Payments, SaaS & PHP / Laravel As a Full Stack Developer and React Node.js Developer, I develop SaaS platforms, marketplaces, and payment systems. I also have strong experience with PHP and Laravel, building and maintaining backend services and APIs. As a Full Stack Developer, I’ve integrated PHP systems with modern stacks like React.js and migrated legacy PHP / Laravel backends to MERN stack and Supabase solutions. 💰 $10M+ revenue generated 📉 Reduced checkout drop-offs by 20–30% 📈 Increased AOV by 20–25% ⚙️ Additional Expertise 30+ projects as a Full Stack Developer and Full Stack React Developer Strong background as a React Node.js Developer Deep expertise in SQL, PostgreSQL, MySQL, and MongoDB Hands-on experience with the MERN stack across production systems Experience with Supabase, Supabase Postgres, and real-time apps AI integrations (OpenAI, ChatGPT) as a React Developer Experience with PHP, Vue, and Svelte Built dashboards, PWAs, and SaaS platforms as a Full Stack Developer Reduced bugs by 30% and improved release cycles by 25% 🤝 Why Work With Me Reliable Full Stack Developer with proven results Experienced React Node.js Developer and MERN stack specialist Strong expertise in React.js, Next.js, and backend systems Solid experience with MongoDB, SQL, PostgreSQL, MySQL, Supabase, and PHP / Laravel Focus on business outcomes, scalability, and performance If you’re looking for a Full Stack Developer, Full Stack React Developer, React Node.js Developer, or MERN stack developer with strong experience in MongoDB, Supabase, SQL, PostgreSQL, MySQL, and PHP / Laravel — let’s connect. 👉 Click "Invite" or "Hire" to get started.