Platform Security Lead - Infrastructure & Identity Security | Proprietary Trading and Investment Firm

[Up to c. $325k Comp Package | Hybrid Working]Role OverviewWe’re representing a technology-led proprietary trading and investment firm operating across global markets. The business combines quantitative research, software engineering and sophisticated infrastructure to support trading activity at scale, with a culture that places heavy value on technical depth, collaboration and practical problem-solving.This is a hands-on leadership role within Platform Security, focused on protecting the core systems that underpin the firm’s global technology environment. You’ll lead a small team while remaining close to engineering delivery across identity, endpoint, server, operating system and emerging AI platform security. The role is well suited to someone who can set direction, mentor strong engineers and still engage directly with complex technical problems...Key ResponsibilitiesGuide the day-to-day technical work of a platform security group responsible for foundational infrastructure and enterprise systemsShape the roadmap for securing identity platforms, endpoint estates, server environments and newer infrastructure servicesImprove defensive controls across mixed operating system environments, including Windows, Linux and macOSWork closely with infrastructure and engineering teams to turn security requirements into practical, scalable implementationsStrengthen access control and directory security across enterprise identity platforms such as Active Directory and Entra IDCreate tooling, automation and repeatable workflows that improve security outcomes without adding unnecessary frictionEstablish pragmatic security patterns that help engineering teams move quickly while reducing platform-level riskStay hands-on across architecture reviews, incident support, troubleshooting and complex technical deliveryContribute to security strategy around cloud platforms, AI-adjacent infrastructure and other evolving technology areasHelp mature the platform security function into a proactive engineering capability focused on long-term resilienceWhat You’ll Bring…8-14 years’ experience across platform security, infrastructure security, systems engineering or related technical security rolesProven experience leading security engineers or driving complex cross-functional security initiativesStrong background securing mixed operating system environments across Windows, Linux and macOSDeep understanding of identity and access management, including Active Directory, Entra ID and privileged access conceptsExperience building internal security tooling or automationExperience with endpoint, server and infrastructure security toolingStrong systems, networking and infrastructure fundamentalsExposure to cloud security, AI platform security or modern infrastructure security environmentsHands-on engineering mindset, with the ability to design, build and automate security improvementsAbility to influence engineering and infrastructure teams without slowing deliveryStrong communication skills and the judgement to balance security, reliability and developer productivity(Preferred) Background in trading, financial technology, large-scale engineering or similarly demanding technical environments..