As a Senior Software Engineer at Fountain, you will collaborate with engineers, designers, and product managers to build user-centered web applications that help organizations improve employee retention. Success requires a track record with rich enterprise products, strong problem-solving skills, and a solid technical background in frontend/backend development, data structures, and architecture. Teams are organized into product squads that independently own product health and market fit. We move quickly; you will operate with autonomy typical of early-stage teams in a globally distributed organization. What you’ll be doing:- Design, develop, test, and maintain product features and enhancements- Collaborate closely with product and design to ship features- Review and collaborate on other developers’ work- Implement RESTful APIs; build functionality in Express/Node.js backend; extend our MongoDB model- Ensure quality, reliability, operations, and security of products- Identify and address performance bottlenecks; optimize for speed, scalability, and usability- Stay current with industry trends to enhance UX What you should bring:- 5+ years of full-stack software engineering experience- Proven experience in product-oriented software development- Proficiency with React, TypeScript, MongoDB, Express (must have); TailwindCSS, MUI, Vite; Ruby on Rails (nice to have); testing with Vitest/Jest and Playwright- Strong problem-solving; critical thinking about user interactions and system architecture- Ability to work independently with limited information- Excellent communication skills in English Nice to Have:- Experience in B2B SaaS startups and remote international settings- Familiarity with event-driven/serverless/high-volume architectures, API strategies, MongoDB, AWS, microservices, web security, Agile methods- Experience in Agile environments and cross-functional collaboration; startup/international backgrounds appreciated