Senior IT Security Engineer - SIEM

Location: London (2 days per week in office)
Contract: 6 Month Fixed-Term Contract (Extensions expected)

A leading international professional services firm is seeking an experienced SOC Engineer to join its Information Security team on a 6-month fixed-term basis.

This is an excellent opportunity for a security professional with strong SIEM engineering expertise who enjoys building and enhancing security monitoring capabilities rather than purely operating within a traditional analyst function.

Working closely with the Information Security Operations Manager and wider security team, you will play a key role in driving the maturity of the organisation's SIEM platform, improving detection capabilities, onboarding new log sources, and supporting security operations across a global environment.

Key Responsibilities

• Enhance and optimise SIEM performance, coverage and detection capability
• Onboard and integrate new log sources across cloud, infrastructure, endpoint, identity and application platforms
• Develop and maintain parsers, connectors and ingestion workflows
• Build, test and tune detection use cases aligned to MITRE ATT&CK methodologies
• Create and improve correlation rules, dashboards and alerting mechanisms
• Support SOC investigations through advanced querying, enrichment and data analysis
• Implement automation and orchestration capabilities to improve incident response processes
• Produce and maintain technical documentation relating to SIEM architecture, data models and detection content
• Collaborate with internal technology teams and third-party vendors to improve security visibility and monitoring

Required Experience

• Strong hands-on experience administering and engineering enterprise SIEM platforms such as Microsoft Sentinel, Splunk, QRadar, LogRhythm, Exabeam, ArcSight or Elastic
• Experience onboarding and integrating diverse log sources
• Strong understanding of log formats including JSON, Syslog, XML and CEF
• Experience building and tuning correlation rules, detections, searches and dashboards
• Knowledge of SOAR technologies and security automation
• Good understanding of infrastructure, networking, cloud platforms, endpoint security and identity technologies
• Experience with Scripting and automation using Python and/or PowerShell
• Strong understanding of cyber security frameworks including MITRE ATT&CK and threat hunting methodologies

Desirable Experience

• Experience within highly regulated environments
• Knowledge of Microsoft Defender and SentinelOne
• Experience with DLP technologies
• Exposure to cloud services including Azure, AWS or GCP
• Threat intelligence and threat hunting experience
• Relevant industry certifications such as SC-200, SC-100, CISSP, SSCP, GIAC or equivalent

What's on Offer?

• Opportunity to make a genuine impact on the maturity of a global security operation
• Exposure to enterprise-scale security tooling and projects
• Collaborative and supportive security team
• Flexible hybrid working arrangement
• International professional services environment

Please note that this position requires attendance in the London office two days per week and is offered as a fixed-term employment contract rather than a day-rate consultancy engagement.