Senior Security Analyst in London

Why work for us?

A career at Janus Henderson is more than a job, it's about investing in a brighter future together.

Our Mission at Janus Henderson is to help clients define and achieve superior financial outcomes through differentiated insights, disciplined investments, and world‑class service.

We will do this by protecting and growing our core business, amplifying our strengths and diversifying where we have the right.

Our Values are key to driving our success, and are at the heart of everything we do: Clients Come First - Always | Execution Supersedes Intention | Together We Win | Diversity Improves Results | Truth Builds Trust If our mission, values, and purpose align with your own, we would love to hear from you!

• Your opportunity
• Detection & Response
• Act as a senior escalation point for complex/high‑severity alerts across SIEM, EDR, Cloud and Identity platforms.
• Lead end‑to‑end incident response (investigation, containment, eradication, and post‑incident review).
• Coordinate immediate mitigation actions across infrastructure, network, and legal teams to isolate compromised environments, stop data exfiltration, and minimize downtime.
• Define and drive the strategic direction for incident response services, ensuring they align with emerging threats.
• Build, develop and oversee cyber security playbooks.
• Correlate alerts with threat intelligence and business context to assess risk and impact.
• Produce clear investigation summaries for technical and non‑technical stakeholders.
• Identify potential security risks and document clear, actionable remediation options or mitigating controls aligned with industry best practices.
• Support preservation of digital evidence and coordinate with Incident Response Retainer for forensic collection.
• Support day‑to‑day security operations and business inquiries.
• Threat Hunting & Proactive Detection
• Conduct proactive threat hunting using queries, dashboards and behavioral analytics.
• Identify gaps using frameworks such as MITRE ATT&CK and translate findings into improved detections and playbooks.
• Tune alerts and detections to reduce noise while maintaining coverage.
• Validate and manage exclusions with clear risk assessment and documentation.
• Work with Detection Engineering to enhance detection logic and alert quality.
• AI‑Assisted Investigation & Tooling
• Use AI-enabled features across SOC tooling to accelerate analysis and investigations.
• Initiate improvements to tooling, workflows, and AI effectiveness.
• Support development of safe and consistent AI usage standards within the SOC.
• Collaboration & Mentoring
• Mentor junior analysts and support their development.
• Provide leadership during incidents and contribute to continuous SOC improvement.
• Collaborate with Security Engineering to support automation and security tooling.
• Collaborate with stakeholders and support partnerships with internal teams and external vendors to improve vulnerability remediation.
• Provide regional handovers to ensure continuity and adherence to operational standards across regions.
• Assist in incorporating regulatory compliance requirements such as SOX and GLBA into the organization’s security roadmap.
• What to expect
• Hybrid working and reasonable accommodations.
• Generous holiday policies.
• Excellent health and wellbeing benefits including corporate membership to Wellhub.
• Paid volunteer time to step away from your desk and into the community.
• Support to grow through professional development courses, tuition/qualification reimbursement and more.
• Maternal/paternal leave benefits and family services.
• All employee events including networking opportunities and social activities.
• Lunch allowance for use within our subsidized onsite canteen.
• Must have skills
• 3+ years’ experience as a Senior SOC Analyst within an internal SOC environment.
• Proven hands‑on experience with Incident Management.
• Knowledge of leveraging vulnerability management and cyber threat intelligence capabilities.
• Strong collaboration skills working with application and infrastructure teams within a security context.
• In‑depth working knowledge of security best practices and frameworks (e. g., MITRE ATT&CK, OWASP Top10, NIST).
• Excellent verbal and written communication skills.
• Ability to manage multiple projects and tasks.
• Analytical ability to capture and summarize information, find solutions to various tactical and strategic problems and prioritize work.
• Knowledge of public cloud infrastructure (Saa S, Iaa S, and Paa S).
• Knowledge of SIEM and EDR tools.
• Knowledge of detection engineering concepts and use case lifecycle management.
• Clear, confident communicator under pressure.
• Proactive and curious, with a continuous improvement mentality.
• Nice to have skills
• 5+ years of experience within Incident Response.
• Experience using AI or machine learning features within security products.
• Experience with SOAR workflows and automating manual tasks.
• Experience working in regulated or large‑scale enterprise environments.
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