Mattermost

We’re helping the world build better software by aligning teams, tools, and processes at each stage of the development lifecycle. Our customers use Mattermost to increase their productivity, build and execute scalable workflows, and collaborate outside of code — all while contributing to a shared, flexible, and extensible platform built just for them.

We’re committed to open source and our community of over 4,000 contributors worldwide. At Mattermost, you get to build open source software benefiting thousands of companies, institutions, schools, and nonprofits around the globe.

27 Mar, 2026
Mattermost USA
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 runs on-premises and in private clouds, delivering secure messaging, file sharing, workflow automation, audio/screenshare, and project management—all with full data and operational control. Mattermost powers high-stakes workflows across mission planning, real-time, real-world operations, DevSecOps, incident response, and cyber defense—enabling secure collaboration from tactical edge and DDIL environments to enterprise HQ. Teams operate across web, desktop, and mobile, with embedded interoperability for Microsoft Teams, Outlook, and Microsoft 365. To learn more, visit  www.mattermost.com   Mattermost Federal | TS/SCI Environments Mattermost Federal builds secure collaboration platforms used by U.S. defense, intelligence, and national security organizations operating in the most...
27 Mar, 2026
Mattermost HI, USA
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 runs on-premises and in private clouds, delivering secure messaging, file sharing, workflow automation, audio/screenshare, and project management—all with full data and operational control. Mattermost powers high-stakes workflows across mission planning, real-time, real-world operations, DevSecOps, incident response, and cyber defense—enabling secure collaboration from tactical edge and DDIL environments to enterprise HQ. Teams operate across web, desktop, and mobile, with embedded interoperability for Microsoft Teams, Outlook, and Microsoft 365. To learn more, visit  www.mattermost.com Mattermost Federal | TS/SCI Environments Mattermost Federal builds secure collaboration platforms used by U.S. defense, intelligence, and national security organizations operating in the most...
27 Mar, 2026
Mattermost USA
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 runs on-premises and in private clouds, delivering secure messaging, file sharing, workflow automation, audio/screenshare, and project management—all with full data and operational control. Mattermost powers high-stakes workflows across mission planning, real-time, real-world operations, DevSecOps, incident response, and cyber defense—enabling secure collaboration from tactical edge and DDIL environments to enterprise HQ. Teams operate across web, desktop, and mobile, with embedded interoperability for Microsoft Teams, Outlook, and Microsoft 365. To learn more, visit  www.mattermost.com Mattermost is seeking an experienced and visionary Lead Site Reliability Engineer (SRE) to guide the architecture, reliability, and operational excellence of the infrastructure powering our...
27 Mar, 2026
Mattermost USA
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 runs on-premises and in private clouds, delivering secure messaging, file sharing, workflow automation, audio/screenshare, and project management—all with full data and operational control. Mattermost powers high-stakes workflows across mission planning, real-time, real-world operations, DevSecOps, incident response, and cyber defense—enabling secure collaboration from tactical edge and DDIL environments to enterprise HQ. Teams operate across web, desktop, and mobile, with embedded interoperability for Microsoft Teams, Outlook, and Microsoft 365. To learn more, visit  www.mattermost.com Mattermost is seeking a Senior React Native Engineer to join our mobile engineering team and build resilient mobile experiences for mission-critical industries like defense, intelligence, and critical...
27 Mar, 2026
Mattermost United Kingdom
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 runs on-premises and in private clouds, delivering secure messaging, file sharing, workflow automation, audio/screenshare, and project management—all with full data and operational control. Mattermost powers high-stakes workflows across mission planning, real-time, real-world operations, DevSecOps, incident response, and cyber defense—enabling secure collaboration from tactical edge and DDIL environments to enterprise HQ. Teams operate across web, desktop, and mobile, with embedded interoperability for Microsoft Teams, Outlook, and Microsoft 365. To learn more, visit  www.mattermost.com Mattermost is hiring a  Senior Security Engineer to play a key role in safeguarding our company, SaaS platforms, and IT infrastructure. As a vital member of our Security team, you'll collaborate with...