Senior Software Engineer (React/C#)

Senior Software Engineer We are seeking a Senior Software Engineer to join a collaborative product development team building and enhancing a modern software platform for the resale industry. This role will contribute across the full stack, partnering with engineering, QA, UX, and Product to deliver high-quality, scalable software. Responsibilities Design, develop, test, and maintain features across the full software stack. Build and enhance web applications, APIs, and integrations using modern technologies. Develop a deep understanding of the platform, including POS, product appraisal, and inventory management capabilities. Write comprehensive unit, integration, and end-to-end tests to ensure software quality and reliability. Improve application performance, scalability, and system reliability. Troubleshoot production issues and support critical software incidents as needed. Contribute to development processes, release practices, and the Shape Up product development methodology. Mentor engineers and promote strong engineering, collaboration, and coding practices. Qualifications 6+ years of experience developing modern web applications. Strong backend development experience with C#/.NET or a similar language and framework. Significant experience with modern frontend frameworks, particularly React and TypeScript . Strong experience developing and integrating APIs. Experience with automated testing, including unit, integration, and end-to-end testing. Experience with relational databases such as PostgreSQL and modern cloud-native environments. Strong software engineering fundamentals, attention to detail, and problem-solving skills. Excellent communication and collaboration skills. Ability to independently design and produce high-quality code without relying on AI/LLM tools.