Sachin J.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 Nov 5, 2026.

I’m a Senior Mobile & Full-Stack Developer with 12+ years of experience, specializing in building high-performance mobile and web applications for startups, businesses, and established companies. I combine strong product development experience with modern mobile architecture to build applications that are scalable, secure, responsive, and ready for production. From a new MVP to a complex enterprise application, I can take your project through the complete lifecycle—from architecture and UI implementation to backend/API integration, testing, deployment, and ongoing maintenance. 🚀 Core Mobile Expertise iOS Development Swift Objective-C Native iOS applications REST API integration Push notifications In-App Purchases Apple services & SDK integrations TestFlight & App Store deployment Android Development Kotlin Java Native Android applications REST API integration Push notifications Google services & SDK integrations Play Store deployment Cross-Platform Development Flutter React Native Cross-platform application architecture Shared business logic Responsive mobile interfaces Native SDK integrations 💻 Full-Stack Development I can build both the mobile experience and the backend infrastructure behind it. Frontend React Angular Vue.js TypeScript / JavaScript HTML5 / CSS3 Bootstrap Responsive web applications Backend Node.js Python Django Laravel Ruby on Rails REST APIs JSON / XML AWS Lambda Firebase ☁️ Cloud, Backend & APIs I have experience building and integrating cloud-based backend systems using: AWS AWS Lambda Firebase Amazon RDS REST & SOAP APIs Serverless architectures Authentication & authorization Real-time data systems Cloud-based application infrastructure 💳 Payments & Third-Party Integrations I can integrate the services your application needs, including: Stripe PayPal Braintree Klarna Credit/debit card payments In-App Purchases Social login Google Maps Social media SDKs Analytics & third-party APIs 💬 Real-Time Communication & Media I've worked on applications involving real-time communication, messaging, and media processing, including: Chat & messaging WebSockets XMPP / Jabber WebRTC OpenTok Real-time notifications Live streaming Audio/video applications Image & video processing 🗄️ Database & Data Technologies MySQL MongoDB SQLite Core Data Amazon RDS Firebase API-driven data architectures 📱 Application Experience I've developed applications across multiple business models and use cases, including: Business Automation Apps Geo-Location & Tracking Apps Healthcare & Fitness Applications Real-Time Video & Audio Platforms Taxi & Ride-Sharing Applications Booking & Service Platforms Social & Messaging Applications eCommerce & Shopping Apps Real Estate Applications News & Event Platforms Calendar & Scheduling Applications QR Code & Scanning Applications 🏗️ Architecture, Modernization & Maintenance I can also step into an existing project and help you: Review and improve application architecture Modernize legacy mobile applications Fix bugs and production issues Improve application performance Add new features Integrate new APIs and SDKs Improve security Refactor existing code Connect mobile apps with new backend systems Prepare applications for production and store submission 🔐 Security & Quality For production applications, I focus on: Secure API communication Authentication & authorization Secure data handling Code quality Performance optimization Testing and debugging Reliable release processes 🛠️ Development & Project Tools Git GitHub Bitbucket Jira Trello Slack Redmine TestFlight App Store Connect Google Play Console ⭐ Why Work With Me? 12+ years of development experience 101+ applications/projects delivered B2B-verified client experience Mobile + backend + API expertise Modern iOS, Android & cross-platform development Clear and proactive communication Flexible collaboration across time zones Long-term maintenance and support I believe great software is about more than writing code. It requires understanding the business goal, user experience, technical requirements, and long-term scalability of the product. Whether you're building a new mobile product, improving an existing application, or need a reliable developer to take ownership of a complex project, I can help take it from concept to production and beyond. Have a project in mind? Send me your requirements, and let's discuss the best technical approach.