At Mattermost, we build the #1 collaborative workflow solution for defense, intelligence, security, and critical infrastructure organizations. Trusted by governments, financial institutions, and technology companies, our platform enables secure, efficient operations for the world’s most critical teams.
We’re dedicated to empowering organizations to operate with confidence, reducing risks, and accelerating productivity. Guided by our core values of Customer Obsession, Earn Trust, Self Awareness, Ownership and High Impact, we collaborate closely with our customers to deliver solutions that meet complex needs and drive success.
To learn more, visit www.mattermost.com
Mattermost is seeking a highly skilled and experienced Software Engineer II to design, develop, and maintain cutting-edge solutions that enable secure, efficient, and collaborative workflows for mission-critical industries like defence, intelligence, and critical infrastructure.
As a Software Engineer II, you’ll work at the intersection of technology and user needs, delivering features that solve real-world problems, particularly in domains where precision, security, and collaboration are paramount. This is more than a coding role—it’s a product engineering role focused on building products with a direct impact on critical workflows. Your contributions to our open-core platform using your personal GitHub account will empower the broader developer community while leaving a lasting professional legacy.
The person in this role will join a fast-paced, flexible full stack team responsible for developing and delivering impactful features and systems that empower collaboration for the world’s most critical organisations. Do you have a passion for designing and developing high-impact products? Do you want to work with a well-oiled, collaborative and highly senior team? Do you want to make an impact on open source? Help us build and grow one of the largest React and Go open-source projects.

REQUIREMENTS

• BS in Computer Science, Computer Engineering, or related field/experience
• 3+ years of experience working as a full-stack software engineer building scalable, production-ready systems
• Strong skills in our technology stack: TypeScript, React, React Native, Go, and/or PostgreSQL
• Expertise in full-stack development, including designing APIs, implementing frontends, creating fault-tolerant back-end code, and optimising database performance
• Enthusiasm for and experience developing with AI tools like Claude Code, Cursor and/or GitHub Copilot
• Solid understanding of modern development workflows, including CI/CD pipelines, distributed systems, and cloud infrastructure
• Comfortable working as a product engineer, focused on solving customer-centric problems in addition to writing code
• Strong written and verbal communication skills suitable for diverse audiences
• Capable of working independently across multiple time zones while actively engaging in team collaboration

• Design, build, and maintain software solutions using TypeScript, React, React Native, and Go to deliver secure and scalable products
• Take full-stack ownership by developing user-facing features, back-end architectures, APIs, and integrations
• Contribute to Mattermost’s open-source platform through GitHub, creating impactful open-source solutions for both internal and external ecosystems
• Collaborate with product managers, designers, and engineers to prototype and ship tailored solutions for complex workflows
• Mentor peers through code reviews, technical discussions, and knowledge sharing, fostering a culture of excellence
• Implement and maintain unit/integration/e2e tests to ensure code quality and robust platform performance
• Diagnose and resolve bugs or performance bottlenecks, ensuring security and reliability in deployments
• Leverage customer and industry feedback to iterate rapidly and deliver adaptable, high-value solutions
• Lead the development of mission-critical, customer-focused solutions, anticipating the evolving needs of defence, intelligence, and infrastructure industries