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Senior Security Specialist – Penetration Testing

United Kingdom - Home Based💼 Full-time🗓 2026-07-28 → 2026-09-25

Core

Planning and executing end-to-end penetration tests across web applications, APIs, thick clients, and cloud-native infrastructures to uncover vulnerabilities and improve security posture.

Role type

Senior hands-on IC penetration tester

Builds

Security assessments and remediation guidance for LSEG's internal systems and applications

Domain

Financial markets infrastructure / Cybersecurity

Deliverable

production ML models | product features | dashboards & analysis | research | client delivery | infrastructure | physical/clinical work

Required skills

Penetration testing (Web Apps, APIs, Active Directory, Cloud), Cloud platforms (AWS, Azure, GCP), Containerization (Docker, Kubernetes), Custom scripting, Technical reporting, Risk assessment

Preferred skills

Threat modelling, Automation of pentesting tasks, R&D in offensive security techniques

Technologies

Burp Suite, Command-line tools, Docker, Kubernetes, AWS, Azure, GCP

Responsibilities

Conduct in-depth penetration tests on applications, infrastructure, and cloud environments; Take full ownership of assigned pentesting engagements end-to-end; Compile technical scoping documents and track assessment metadata; Document findings clearly and provide actionable remediation guidance; Collaborate with application teams to scope, execute, and report on security assessments; Develop and maintain custom tools, scripts, and exploits to support testing activities

Seniority

Senior, hands-on IC

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