Senior Security Engineer - Detection & Response - EU

Senior Security Engineer – Detection & Response – EU/UK

Remote, UK

We are seeking a UK-based Senior Security Engineer to join our Security Operations and Response Team as a senior individual contributor.

In this role, you will investigate and respond to security incidents across Marqeta’s environment, proactively monitor for cyber threats, and serve as incident commander during security events of varying severity. You will contribute to the development and improvement of response methodologies aligned with the NIST Incident Response Lifecycle and help maintain cybersecurity incident response documentation. This position requires strong expertise in incident response, digital forensics, threat hunting, and security monitoring technologies.

You will collaborate across teams, contribute to detection engineering efforts, 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. We’d love for you to join us!

• 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 incident commander during security events, directing investigation strategies and coordinating cross‑functional response efforts
• Execute incident response activities aligned with the NIST Incident Response Lifecycle to detect, contain, eradicate, recover, and learn from cybersecurity incidents
• Contribute to the maintenance and improvement of the Cybersecurity Incident Response Plan (CIRP), playbooks, runbooks, and standard operating procedures to ensure consistent and effective response operations
• Participate in 24x7x365 on‑call rotations, providing skilled guidance during security incidents and contributing to thorough post‑incident reviews
• Research threat intelligence sources and contribute to 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
• Contribute to detection coverage mapped to MITRE ATT&CK framework, identifying gaps in visibility and supporting detection development prioritization based on threat intelligence and business risk
• Coordinate with HR, law enforcement, response retainers, and cyber insurers as required, including support on cyber‑crime financial fraud use cases
• Support the development of less‑experienced security team members through knowledge sharing, pair investigations, and leading by example
• Partner with Fraud, Compliance, and Risk teams on security events involving payment systems, cardholder data, or regulatory reporting obligations under PCI DSS and related frameworks

• 5+ years of hands‑on experience in security operations with strong expertise in incident response, digital forensics, and threat hunting
• Experience serving as an incident commander or leading incident response work streams, with the ability to make sound decisions under pressure
• Strong knowledge of the NIST Incident Response Lifecycle and experience contributing to incident response documentation and procedures
• Proficiency with security monitoring and forensic tools including EDR, SIEM, and SOAR systems
• Experience developing detections‑as‑code, including familiarity with version control, CI/CD pipelines, and detection testing frameworks
• Working knowledge of MITRE ATT&CK and experience using it to assess detection coverage and map threat actor TTPs
• Experience contributing to post‑incident reviews and implementing security improvements based on lessons learned
• Solid understanding of threat actor TTPs and ability to apply threat intelligence to enhance detection and response capabilities
• Experience tuning security solutions and developing automation workflows to…