Staff Security Engineer - EU / UK in London

We are seeking a UK-based Staff Security Engineer to serve as a technical leader within our Security Operations and Response Team. As a senior technical responder, you will lead our incident response program, proactively monitor Marqeta's environment for cyber threats, and serve as incident commander during security events of all severity levels. You will establish response methodologies aligned with the NIST Incident Response Lifecycle, maintain the cybersecurity incident response plan, and drive continuous improvement of our security operations. This position requires extensive expertise in incident response, digital forensics, threat hunting, and security monitoring technologies. You will provide technical leadership across the organization, mentor team members, and participate in 24x7 on-call rotations. The role reports to the Manager of Security Operations and Response. This role can be performed remotely anywhere in the UK, or from our London, UK office.

The Impact You’ll Have

• Proactively monitor Marqeta's environment for cyber threat activity and manage day-to-day security alerts through timely analysis, triage, and appropriate response actions.
• Serve as the incident commander during security events of all severity levels, directing investigation strategies and coordinating cross-functional response efforts.
• Deliver NIST Incident Response Lifecycle aligned services to prepare for, detect, contain, eradicate, recover, and learn from cybersecurity incidents.
• Work with the CISO to maintain the Cybersecurity Incident Response Plan (CIRP), ensuring alignment with government and law enforcement reporting requirements.
• Document and maintain Security Operations processes, procedures, playbooks, and runbooks to ensure consistent and effective response operations.
• Participate in 24x7x365 on-call rotations, providing expert-level guidance during security incidents and conducting thorough post-incident reviews.
• Proactively research threat intelligence sources to develop and lead hypothesis-driven threat hunting initiatives to uncover threats in corporate and production environments.
• Work closely with Security Engineering to tune security solutions, enhance detection capabilities, and leverage business knowledge to improve security monitoring.
• Design, develop, and maintain detection logic using a detections-as-code approach, collaborating with Security Solution Engineering to deploy detections through CI/CD pipelines into our SIEM and EDR platforms.
• Maintain and expand detection coverage mapped to MITRE ATT&CK framework, identifying gaps in visibility and prioritising detection development based on threat intelligence and business risk.
• Serve as liaison with HR, law enforcement, response retainers, and cyber insurers as required, including coordination on cyber-crime financial fraud use cases.
• Mentor security team members in incident response methodologies while collaborating with senior leadership to communicate security risks and strategic recommendations.
• Partner with Fraud, Compliance, and Risk teams on security events involving.