Riku S.Private profile: Upwork shows its earnings only to signed-in members, so we check it every few weeks, not daily. MRR here is a rough estimate (Upwork's six-month earnings ÷ months active). Last read Jul 17, 2026.

👋 Hi, I’m Riku Sato - a Full-Stack Mobile & Web Developer specializing in building scalable, high-performance applications for startups and growing businesses. I help turn ideas into production-ready apps using modern, in-demand technologies like Flutter, Swift, Kotlin, React, Next.js, and Node.js. 🚀 What I Do Best • Mobile App Development (iOS & Android with Flutter, Swift, Kotlin) • Full-Stack Web Development (React, Next.js, Node.js) • API Development & Integration (REST APIs, third-party services) • Real-time Apps (Firebase, WebSockets) • Database Design (MongoDB, scalable backend systems) • AI-powered features & automation 🔧 How I Work I focus on clean architecture, fast performance, and scalable systems. Whether it's launching an MVP or improving an existing product, I build solutions that are reliable, maintainable, and ready to grow. I’ve worked on projects involving complex API integrations, real-time data systems, and user-focused mobile apps where performance and UX really matter. 💡 Why Clients Choose Me • Clear and consistent communication • Fast turnaround with high-quality code • Ownership mindset - I treat your product like my own • Focus on business results, not just code 📈 If you're looking for a developer who can build, improve, and scale your app efficiently, I’m ready to help.