Senior Security Engineer

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 a globally distributed group of top talent to design, monitor, and implement security processes that ensure the resilience of our services. Join us to take your career to the next level while shaping the future of secure platforms in a fast-paced, innovative environment!
You will be responsible for the implementation of additional security tooling, hardening, and/or processes across the company. Coordinating and collaborating with relevant stakeholders, gathering requirements, and leading implementation.
Responsibilities include:
Lead security and IT projects to enhance security posture of infrastructure and company
Detect, respond to, and remediate security incidents
Contribute to the development, review, and enforcement of company-wide security policies and processes
Administration of company-wide IAM solution
Administration of security monitoring infrastructure
Contribute to growing our security incident response, forensic, and endpoint management programs
Engage closely with North American and international staff.
Partner with Engineering teams to assist and mitigate risks related to AI-enabled tools, services, and workflows.
Explore and implement AI and automation workflows as part of detection, analysis, and response processes.
Required Background/Skill
Bachelor's degree in Computer Science or related fields, or significant professional security experience
3+ years of demonstrated experience in security engineering and incident response
Experience with security monitoring systems
Experience with security controls for cloud environments such as AWS, GCP and/or Azure
Curiosity and practical experience evaluating security implications of AI systems, automation, or AI-assisted workflows
Experience with identity and access management
In-depth knowledge of Linux systems
Experience with Kubernetes and Docker
Experience with infrastructure automation and software delivery.
Excellent written and verbal communication skills
Demonstrable teamwork skills and resourcefulness
Experience managing security of Microsoft 365 and Google Workspace tenants.
Applicants must meet eligibility requirements for access to export-controlled information as defined by U.S. export control laws, including EAR and ITAR.
Preferred Background/Skill
Experience with certification processes such as SOC2, ISO 27000 series, FedRamp, etc.
Experience in one or more programming languages, ideally Go or Python
Certifications in the domain of penetration testing, incident response or computer forensics (e.g. OSCP, GCIH, GCFA, etc.)
Experience working in open-source communities
Past success in critical infrastructure industries including defense, cybersecurity, communications, manufacturing, or other vital functions.
Experience managing endpoint security for a fully remote organization
Mattermost takes a market-based approach to pay and pay may vary depending on your location. The successful candidate’s starting pay will be determined based on job-related skills, experience, qualifications, work location, and market conditions. These ranges may be modified in the future.
Mattermost is an EEO Employer, we are a remote-first, open-source company.
We are continually working to expand our hiring in more countries and regions, ensuring compliance with local laws and regulations, which takes time.
Mattermost values your unique perspective—we welcome all applicants. We encourage individuals from all backgrounds to apply and are committed to assessing candidates based on their skills and qualifications. We do not tolerate discrimination against staff or applicants based on race, religion, national origin, age, disability, pregnancy status, veteran status, or other personal characteristics.
If you require accommodations during the interview process, please let us know—we’re happy to assist.