Senior Software Engineer - Fountain One
Software Engineering
Buenos Aires, Argentina
Posted on Jul 29, 2026
Fountain builds workforce management software for the world's largest hourly employers. We are an agent-first engineering organization where coding and review agents are integrated into our daily workflow. Our platform team builds the critical systems that enable engineers and agents to ship dependable products at scale. What You’ll be Doing: Develop foundational systems; ship platform capabilities; own performance, security, and stability; enhance agentic systems; lead architectural decisions; design reliable code, APIs, and contracts; collaborate across teams; work autonomously; identify problems and ship fixes. What you bring: 5+ years backend-focused engineering; expert systems design; strong API/UX/code judgment; experience with agentic or LLM-based systems; initiative; thrives in autonomy; excellent written communication. Nice to have: Designed APIs/tools for agents; startup experience; event-driven architectures/monorepos/observability.