As a Senior Full-Stack Developer, you will join a mission-critical initiative to build an AI-powered subscription platform for solo professionals (Fount.com). Fount is an independent product unit partially supported by JustAnswer, and you’ll join its core delivery team. We’re developing a category-defining toolset that helps experts get leads, manage communications, and grow their businesses — all enhanced by intelligent AI assistants.
You’ll work across the full stack (.NET Core/C# + React.js), helping build new features like an auction system for lead bidding, expert/customer chats, contracts, and billing tools. Much of the work is greenfield (from the scratch), and you’ll play a key role in defining scalable architecture and shipping impactful features.
What You’ll Do * Design, develop, and maintain full-stack applications, backend logic modules, and front-end experiences using React.js and .NET Core. * Collaborate with Product, UX, and Engineering stakeholders to clarify requirements and contribute to technical planning and documentation. * Conduct code and design reviews, provide architectural input, and mentor junior developers on best practices. * Write and maintain automated unit and integration tests using tools such as Jest, NUnit, or Playwright. * Monitor and support production systems, resolve bugs, run performance audits, and ensure system stability. * Contribute to the implementation of AI-driven features, including prompt-based workflows, RAG pipelines, and personalized assistant flows. * Continuously improve code quality, team velocity, and system reliability through thoughtful technical decisions and rapid iteration.
What We’re Looking For * 5+ years of commercial experience in full-stack software development. * Strong proficiency in .NET Core, C#, and React.js (or deep experience in another modern frontend framework and readiness to learn React). * Experience building and consuming REST APIs, and working with asynchronous backend services. * Familiarity with modern automated testing frameworks (Jest, NUnit, Playwright, etc.). * Comfortable working in a CI/CD environment with agile delivery cycles. * Basic database knowledge and familiarity with performance and scalability considerations. * Proven ability to work independently, own projects end-to-end, and make architectural tradeoffs. * Upper-Intermediate English or higher for effective communication with international stakeholders. * Curiosity and interest in AI-powered applications and emerging technologies.
Perks and Benefits * Time off throughout the year (paid and unpaid) * Professional development support and encouragement * Resources to help improve your overall well-being * Free membership to dive into JA product
About Us We are a San Francisco-based company founded in 2003. Our mission is simple: we help people. We have democratized professional services by connecting customers with verified and vetted Experts who provide reliable answers at any hour and on any budget. JustAnswer members enjoy round-the-clock access to 12,000+ doctors, lawyers, tech support, mechanics, vets, home repair pros, and more. In the last 20 years, we have helped 22 million customers in 196 countries by answering more than 25 million questions.
