Senior Staff Information Security Engineer

We are seeking a Senior Staff Information Security Engineer to help shape and advance security across our hybrid technology estate. Our environment spans AWS and on-premises infrastructure hosted in colocation facilities. You will provide senior technical leadership across both environments, defining secure architecture patterns, building scalable controls, and partnering with Engineering, Product, SRE, and Infrastructure teams to reduce risk without creating unnecessary barriers to delivery. This is a senior individual-contributor role. You will remain hands-on while acting as a trusted technical authority for complex security architecture and engineering decisions. You will lead initiatives that cross teams and technologies, address systemic security challenges, and improve how security is designed and implemented across the organisation. The role is primarily remote, with occasional in-person responsibilities at our Bristol, UK office and, where necessary, our colocation facilities. What you'll do: Lead Infrastructure Security Architecture • Define and evolve security architecture across AWS and our colocation estate. • Establish secure reference architectures, engineering standards, and reusable control patterns. • Provide technical leadership for major infrastructure, platform, and product initiatives. • Identify systemic risks and lead practical, sustainable programmes to address them. Strengthen Cloud and Hybrid Security • Design and improve security across cloud accounts, networks, identities, workloads, and shared services. • Establish effective controls for identity and access management, segmentation, encryption, secrets, logging, monitoring, and workload protection. • Develop preventative guardrails through infrastructure-as-code, policy-as-code, automation, and cloud-native security services. • Improve consistency across the enterprise including cloud, on-premises infrastructure, and the connectivity between them. Partner with Engineering and Product • Engage early in the design of new products, platforms, services, and integrations. • Lead threat modelling, security architecture reviews, and technical risk assessments. • Translate security risks into clear, practical engineering recommendations. • Help teams adopt secure-by-design principles through reusable patterns, tooling, and documentation. Build, Automate, and Apply AI • Design and implement security tooling, integrations, and automated controls. • Embed security capabilities into infrastructure provisioning, engineering workflows, and CI/CD pipelines. • Use AI-assisted tooling to improve scripting, detection development, alert analysis, vulnerability triage, threat modelling, and technical documentation. • Validate AI-generated outputs and ensure AI tools are used with appropriate controls for confidentiality, accuracy, access, and human oversight. Improve Risk Reduction and Resilience • Provide technical direction for vulnerability and exposure management across AWS and on-premises infrastructure. • Identify recurring patterns across incidents, penetration tests, vulnerabilities, and control assessments. • Act as a senior technical escalation point during significant security incidents. • Ensure investigations and lessons learned result in durable architectural and engineering improvements. Provide Senior Technical Leadership • Lead complex security initiatives spanning multiple teams and planning cycles. • Mentor security engineers and provide guidance to engineers in adjacent teams. • Raise the standard of security architecture, automation, documentation, and technical decision-making. • Communicate security risks and recommendations clearly to technical teams, product leaders, and senior stakeholders. What you'll bring: • Significant experience in security engineering, infrastructure security, cloud security, security architecture, or platform engineering. • Deep, hands-on experience securing AWS environments. • Strong knowledge of AWS identity and access management, network architecture, account governance, encryption, logging, monitoring, secrets management, and workload protection. • Experience designing or securing on-premises, data-centre, or colocation-hosted infrastructure. • Strong knowledge of enterprise networking, segmentation, firewalls, secure remote access, privileged administration, and hybrid connectivity. • Experience with infrastructure-as-code, CI/CD security, containerised environments, and cloud-native platforms. • Demonstrated experience designing and implementing automated security controls and engineering solutions. • Proficiency with scripting or software development using Python, Go, or a comparable language. • Practical experience using AI-assisted tooling to improve security engineering and operational workflows. • Experience leading complex initiatives across multiple engineering, infrastructure, or product teams. • Strong knowledge of security architecture,