React / TypeScript Full-Stack Developer for Existing B2B SaaS Platform

We are looking for an experienced Full-Stack Developer to support the continued development of an existing B2B SaaS web application. The platform is already under active development, so this is not a greenfield project. We need someone who is comfortable joining an existing codebase, understanding the current architecture and implementing clearly defined features without unnecessarily rewriting or changing unrelated parts of the application. Our current stack includes: • React • TypeScript • Node.js • PostgreSQL • REST APIs • Git / GitHub Experience with Next.js, AWS, automated testing and production SaaS applications is a strong advantage. The initial engagement will be a small paid fixed-price assignment with a clearly defined scope, expected deliverables and acceptance criteria. If the first assignment goes well, there is potential for additional development packages as the platform continues to evolve. Some parts of the application contain proprietary business logic and will remain restricted. For certain tasks, you may therefore work with predefined TypeScript interfaces, APIs or data contracts without access to the implementation behind them. We are specifically looking for a developer who: • has strong practical experience with React and TypeScript; • is comfortable working with an existing production codebase; • has good knowledge of Node.js, APIs and PostgreSQL; • writes clean, maintainable and well-structured code; • understands automated testing and regression prevention; • works carefully with Git and code review; • follows existing architecture and coding conventions; • does not make unrelated changes outside the agreed scope; • communicates clearly when something is unclear or requires access outside the assigned scope. Important: we are currently looking for an individual developer, not an agency or development team. The selected developer must personally carry out the assigned work. Repository access, source code and project information must not be shared with other developers, agency members or third parties without prior written approval. For the first assignment, we expect the developer to: • work only within the defined technical scope; • provide appropriate tests; • report any issue found outside the scope instead of modifying unrelated code; • document the files changed and the work completed; • provide a clear final delivery report. When applying, please briefly answer the following: How many years of professional experience do you have with React and TypeScript? What experience do you have working on existing SaaS applications rather than building from scratch? What is your experience with Node.js and PostgreSQL? What testing tools do you normally use? How do you normally manage Git, branches, pull requests and code reviews? Do you personally carry out all development work? Are you currently associated with an agency or development team? Do you use AI coding tools such as Cursor, GitHub Copilot, ChatGPT or Claude? How do you handle issues you discover outside the scope of your assigned task? Are you comfortable starting with a small paid fixed-price technical assignment before moving to larger pieces of work? We value clear communication, disciplined development and respect for scope more than speed alone.