Senior Security Engineer in City of London

A Senior Security Engineer is required by a London-based Quantitative Trading firm. As part of a global security team, the incoming engineer will be responsible for engineering and automating security solutions to address the global threat landscape, streamline business execution and further enable firm-wide AI adoption. This is a hybrid working role with a requirement for 4 days in the office per week, so applicants should be within commutable distance of central London or happy to relocate.

Responsibilities:

• AI Security & Emerging Threats
  • Assess and mitigate security risks associated with AI/ML systems and LLM-integrated applications.
  • Develop detections and tooling for AI-related threats (e.g., prompt injection, model abuse, data leakage, adversarial inputs).
  • Work with other teams to embed secure-by-design principles into AI-enabled workloads and features.
  • Contribute to AI threat modelling, model risk assessments, and secure AI lifecycle practices.
  • Monitor developments in AI security research and adversarial techniques, translating insights into defensive controls.
• Security Monitoring and Incident Response
  • Triage and analyse security alerts, identifying genuine threats and eliminating false positives.
  • Lead and document security investigations through to containment, eradication, and recovery.
  • Perform root cause analysis and produce clear post-incident reports with actionable remediation steps.
  • Continuously enhance detection logic, automation, and response playbooks to improve mean time to detect (MTTD) and respond (MTTR) using AI and automation.
  • Partner with engineering and IT teams to remediate vulnerabilities and strengthen security controls.
  • Monitor emerging threats, adversary tactics, techniques, and procedures (TTPs), and translate intelligence into actionable detections.
• Security Engineering & Secure Design
  • Embed security controls into new and existing systems, applications, and cloud platforms.
  • Identify and remediate security risks during design and build phases.
  • Own the implementation, integration and operational support of enterprise security platforms (Zscaler, Purview, Mimecast, Microsoft Defender).
  • Partner with technology teams to implement secure patterns and controls in code and infrastructure.
  • Lead threat modelling sessions and turn outcomes into concrete engineering tasks.
  • Translate security standards and regulatory requirements into practical, deployable controls.
  • Develop and maintain reusable security guardrails, baselines, and automation.

Required Experience:

• Minimum 5 years of experience in a Cyber Security/Detection Engineering role achieved in a complex technology environment.
• Expert programming skills and a clear understanding of one or more languages (e.g., Python, PowerShell, Go, etc.).
• Familiarity with Infrastructure as Code (Terraform, CloudFormation) and DevSecOps practices and configuration management tooling (Puppet/Ansible).
• Strong understanding of security risks, threat vectors, and monitoring techniques across Linux and/or Windows environments.
• Proven experience designing, building, and tuning detections (SIEM/EDR), conducting detection engineering, and supporting security tooling/infrastructure.
• Experience in incident response, threat hunting, and forensic analysis.
• Knowledge of network security architecture and application security principles.

In addition to working in a technically challenging and highly stimulating environment, the firm also offers a highly lucrative financial compensation package of £250,000 - £300,000 per annum.