Staff Full Stack Engineer

Mattermost is a collaborative workflow platform serving defense, intelligence, security, and critical infrastructure organizations. The Staff Full Stack Engineer will set the technical direction and scale the core web platform across Go backend and React/TypeScript frontend systems. The role will drive architecture, AI-agentic engineering practices, testing strategy, API design, security and compliance initiatives, mentorship, and open-source technical direction.

Responsibilities:

• Define and drive the technical architecture and roadmap for Mattermost’s core web platform across multiple engineering teams, spanning Go, React, TypeScript, PostgreSQL, and Redis
• Set org-wide standards and best practices for AI-agentic engineering workflows — going beyond personal fluency with tools like Claude Code and Cursor to shape how the broader engineering org adopts them, while retaining accountability for correctness, security, and design decisions
• Lead the internal tooling and testing infrastructure strategy that speeds up delivery for the broader engineering org, not just your immediate team
• Own the testing strategy and quality bar across frontend and backend systems, and hold other engineers accountable to it through design reviews and mentorship
• Drive architectural decisions for REST and WebSocket API design, grounded in deep networking fundamentals
• Partner directly with security, compliance, and product leadership on strategic technical bets tied to our government and enterprise customer requirements
• Mentor senior engineers and act as a technical multiplier across the org
• Contribute to and help shape technical direction for Mattermost’s open-source codebase

Requirements:

• Senior full-stack development experience in Go and React (or a comparable stack), with a track record of owning complex systems end-to-end
• Proven experience designing and owning distributed systems or high-availability service architecture at scale
• Experience designing and consuming REST and WebSocket APIs with solid networking fundamentals
• Relational database experience including PostgreSQL, schema design, and query optimization
• Hands-on daily fluency directing AI coding agents such as Claude Code, Cursor, or Copilot for scaffolding, refactors, code review, and test generation — with the judgment to know when to trust the output and when to take the wheel yourself
• Demonstrated ability to influence technical direction across multiple teams without relying on formal authority
• Experience mentoring senior engineers and raising the technical bar for a broader team
• Comfortable operating in regulated or high-compliance environments (e.g., enterprise security, government, or critical infrastructure requirements)
• Candidates must meet federal eligibility requirements to be considered
• Applicants must meet eligibility requirements for access to export-controlled information as defined by U.S. export control laws, including EAR and ITAR
• Prior experience operating as a staff, principal, or technical lead engineer at another company
• Experience maintaining (not just contributing to) an open-source project
• Program-level familiarity with compliance frameworks relevant to defense or government customers (e.g., FedRAMP, ITAR)
• Experience helping scale engineering practices or standards across a growing organization
• Background in defense, intelligence, or critical infrastructure products
• Experience building tools, skills, or workflows on top of AI coding agents including MCP servers, agent skills, or CI-integrated agents