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Mattermost is seeking a Senior Full Stack Engineer to build and scale its core web platform serving defense, intelligence, security, and critical infrastructure sectors. The role involves full-stack development across Go backend and React/TypeScript frontend, with a strong emphasis on AI-forward engineering practices.
Key responsibilities include architecting and building full-stack features optimized for scalability and performance using Go, React, TypeScript, PostgreSQL, and Redis. You will leverage AI coding agents such as Claude Code and Cursor as core daily tools while maintaining full accountability for correctness, security, and design decisions. The role involves developing internal tooling and testing infrastructure to accelerate team delivery, owning testing strategy across frontend and backend code, designing and consuming REST and WebSocket APIs, and maintaining security and compliance standards required by government and enterprise clients. You will also contribute to Mattermost's open-source codebase.
Required qualifications include strong full-stack development experience in Go and React or comparable stacks, expertise in designing and consuming REST and WebSocket APIs with solid networking fundamentals, relational database experience including PostgreSQL schema design and query optimization, and hands-on daily fluency directing AI coding agents with judgment about when to trust output versus taking manual control. A bias toward shipping and owning complex software end-to-end without close supervision is essential.
Nice-to-have qualifications include experience with distributed systems or high-availability service architecture, familiarity with enterprise or regulated-environment security requirements, background in defense, intelligence, or critical infrastructure products, open-source contributions, experience on distributed or remote-first teams, and experience building tools, skills, or workflows on top of AI coding agents including MCP servers or CI-integrated agents.
Success is measured by shipping full-stack features using an AI-forward agentic workflow within the first 90 days, building internal tooling and testing infrastructure that measurably speeds up team delivery by month 6, and becoming recognized as the team's driver of agentic engineering practice by year one while deepening ownership of distributed systems and high-availability architecture.
