Senior Security Engineer

<div class="content-intro"><div>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.<br><br></div> <div>To learn more, visit <a href="http://www.mattermost.com/">www.mattermost.com</a></div></div><p>Mattermost is the secure collaboration platform trusted by Global organizations. Our platform runs on-premises, cloud, and in air-gapped environments, enabling mission-critical workflows from the tactical edge to the enterprise HQ, where data sovereignty and operational security are non-negotiable.</p> <p>We are hiring a Senior Security Engineer to protect the people, infrastructure, and tooling that goes into building and hosting Mattermost.

This is a hands-on, high-impact role at the intersection of enterprise security engineering, cloud information security, and AI-enabled threat response.<br><br><strong>Why Join Mattermost</strong></p> <ul> <li>  Fully remote, globally distributed team | no commute, genuine flexibility</li> <li>  Be a key voice in shaping and delivering security strategy</li> <li>  Competitive salary, equity, and

Benefits

with meaningful work attached</li> </ul> <p><strong>The Role</strong></p> <p>As a Senior Security Engineer, you will lead the design and implementation of security tooling, harden our cloud and IT infrastructure, and serve as a key responder to incidents. You will work across a globally distributed team and partner closely with Engineering to manage AI-enabled risk.<br><br><strong>

Key Responsibilities

<br></strong></p> <ul> <li>Lead security and IT projects to enhance the security posture of infrastructure and the company</li> <li>Detect, investigate, and remediate security incidents using SIEM, EDR, and SOAR tooling (e.g. CrowdStrike, SentinelOne)</li> <li>Conduct threat hunting across cloud and endpoint environments using a Zero Trust framework</li> <li>Administer company-wide IAM and security monitoring infrastructure</li> <li>Contribute to security policies, incident response, forensics, and endpoint management programmes</li> <li>Partner with Engineering to assess and mitigate risks from AI-enabled tools and workflows</li> <li>Explore and implement AI/automation in detection, analysis, and response pipelines</li> <li>Engage closely with North American and international staff across time zones</li> </ul> <p><br><strong>Required Background & Skills</strong></p> <ul> <li>  Bachelor’s degree in Computer Science or a related field, or significant professional security experience</li> <li>  3+ years of hands-on experience in security engineering and incident response</li> <li>  Experience with SIEM platforms and security monitoring systems</li> <li>  Experience with EDR tools such as CrowdStrike or SentinelOne</li> <li>  Knowledge of SOAR platforms and automation of security workflows</li> <li>  Familiarity with Zero Trust architecture principles and threat hunting methodologies</li> <li>  Experience with cloud security controls across AWS, GCP, and/or Azure</li> <li>  Strong knowledge of Linux systems and Kubernetes/Docker environments</li> <li>  Experience with IAM solutions and infrastructure automation</li> <li>  Practical experience evaluating security implications of AI systems and AI-assisted workflows</li> <li>  Experience managing security of Microsoft 365 and Google Workspace tenants</li> <li>  Excellent written and verbal communication skills</li> </ul> <p><br><strong>Preferred Background & Skills</strong></p> <ul> <li>Experience with certification processes: SOC2, ISO 27001, FedRAMP, or Cyber Essentials Plus </li> <li>Certifications: OSCP, GCIH, GCFA, or equivalent penetration testing / incident response credentials</li> <li>Experience in Go or Python</li> <li>Background in open-source communities</li> <li>Endpoint security management experience in a fully remote organisation</li> </ul> <p><strong><br>Export Control & Eligibility</strong></p> <p>This role may involve access to information subject to U.S. export control regulations (EAR/ITAR). Applicants should be aware that eligibility

Requirements

may apply. We encourage candidates with questions about this to reach out. Many UK-based security professionals with defence backgrounds will qualify.

We are happy to discuss your specific situation.<br><br></p> <p><span style="font-size: 10pt;"><em>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.</em></span></p> <p> </p><div class="content-pay-transparency"><div class="pay-input"><div class="title">Posting Range</div><div class="pay-range"><span>£76,123</span><span class="divider"> - </span><span>£100,992 GBP</span></div></div></div><div class="content-conclusion"><div>Mattermost is an EEO Employer, we are a remote-first, open-source company.</div> <div> </div> <div>We are continually working to expand our hiring in more countries and regions, ensuring compliance with local laws and regulations, which takes time.</div> <div> </div> <div>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.</div> <div> </div> <div>If you require accommodations during the interview process, please let us know - we’re happy to assist.</div></div>Find Jobs in United Kingdom on Arbeitnow