Staff Full Stack Engineer - Mattermost

About Mattermost

Mattermost is the leading collaborative workflow platform for defense, intelligence, security, and critical infrastructure. Trusted by the U.S. Department of War and Fortune 500s, our platform delivers secure messaging, file sharing, workflow automation, and project management with full data control.

The Role

We are seeking a Staff Full Stack Engineer to set the technical direction for and scale Mattermost’s core web platform. You will drive architecture across our Go backend and React/TypeScript frontend, ensuring our systems meet strict security, compliance, and reliability requirements.

Our engineering culture is AI-forward. We expect engineers to work fluently with AI coding agents (e.g., Claude Code, Cursor) as a core part of their craft.

What You Will Do

• Architectural Leadership: Define the roadmap for the core web platform, spanning Go, React, TypeScript, PostgreSQL, and Redis.
• AI-Agentic Workflows: Set org-wide standards for AI-assisted engineering, shaping how the team adopts tools while maintaining accountability for security and correctness.
• Infrastructure Strategy: Lead internal tooling and testing strategies to accelerate delivery across the organization.
• Technical Mentorship: Act as a technical multiplier, mentoring senior engineers and driving architectural decisions for REST and WebSocket APIs.
• Strategic Partnership: Collaborate with security, compliance, and product leadership on technical bets for government and enterprise customers.

What We Are Looking For

• Core Experience: Senior full-stack development in Go and React (or comparable stacks) with a track record of owning complex, distributed systems.
• Technical Depth: Expertise in REST/WebSocket API design, networking fundamentals, and PostgreSQL schema design/optimization.
• AI Fluency: Daily hands-on experience directing AI coding agents (Claude Code, Cursor, Copilot) for scaffolding, refactoring, and testing.
• Influence: Demonstrated ability to drive technical direction across teams without formal authority.
• Compliance Mindset: Experience operating in regulated environments (e.g., government, defense, or enterprise security).

Why Mattermost

• Mission-Driven: Support critical missions for the U.S. Department of War and global infrastructure operators.
• Remote-First: Work from anywhere with a high-trust, autonomous team.
• AI-Forward: Agentic development is core to our engineering culture.
• Open Source: Contribute to a vibrant community shaping the future of secure collaboration.

U.S. Eligibility & Compliance

This role may require obtaining and maintaining a U.S. government security clearance. Candidates must meet federal eligibility requirements for access to export-controlled information (EAR/ITAR).