Sabbir Hossain P.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 am a Senior Full Stack Engineer who builds complete software ecosystems. I do not just write code; I handle the entire lifecycle from system architecture to deployment and maintenance. My focus is on unifying platforms, ensuring your Web, Mobile, and Desktop applications all work seamlessly together under one robust architecture. For core development, I specialize in the Microsoft Ecosystem and Cross-Platform Mobile solutions. I build secure, scalable backends using C# .NET Core and Postgresql. For the frontend, I deliver pixel-perfect mobile applications using Flutter for iOS and Android, and responsive web interfaces using React.js or Blazor. Unlike many web-only developers, I also possess the specific ability to build heavy-duty Desktop software using WPF and Electron for offline or industrial use cases. Beyond standard development, I am an expert in AI integration and Automation. I build custom bots using Python, Selenium, and C# to automate repetitive business workflows and data scraping tasks. I also integrate AI agents into software, utilizing both cloud APIs like OpenAI and cost-effective Offline Local LLMs like Llama to make your applications intelligent and privacy-focused without high recurring costs. I handle my own DevOps to ensure delivery is smooth. This includes setting up CI/CD pipelines with Docker, managing Linux and Windows servers on Azure or AWS, and ensuring high availability. If you are looking for a Product Engineer who can take a complex idea and build everything from scratch to the final release, I am ready to help.