Security Infrastructure Systems Engineer

In this role you will secure and optimize SSTL's core IT infrastructure, aligning security with design and operations. You will work closely with infrastructure, networking, and application teams to embed security across the stack, maintain resilience, and support compliant operations. You’ll handle vulnerability management, access control, logging, encryption, and incident response while contributing to upgrades and resilience initiatives. This role offers hands-on security engineering in a fast-paced environment with cross-functional collaboration and incident readiness.

• Maintain infrastructure services to agreed availability, performance and security standards
• Implement secure configurations and system-hardening standards
• Review and remediate infrastructure vulnerabilities
• Support access control processes, including access reviews, privileged access checks, and enforcement of least privilege principles
• Support endpoint/server security controls
• Ensure appropriate logging and security monitoring is enabled and reviewed
• Support encryption and certificate-management requirements
• Review infrastructure against security standards and vendor recommendations
• Identify unsupported and end-of-life systems and associated risks
• Support security improvements across existing infrastructure
• Oversee and engage in system upgrades, patching, configuration changes and lifecycle-management activities
• Monitor Security and compliance within the SSTL infrastructure capacity, performance, availability and health
• Diagnose and resolve security incidents and problems
• Support backup, recovery, business continuity and disaster-recovery arrangements
• Participate in infrastructure projects, migrations and technology refresh programmes
• Manage the security of the infrastructure through appropriate change, configuration and release-management processes
• Participate in Cyber Security Incident Response Team (CSIRT) activities, including incident investigation, containment, recovery, and continuous improvement of incident readiness

• 3–5+ years of experience in security analysis, infrastructure, DevSecOps, or a related role
• Hands-on experience securing cloud platforms such as AWS, Azure, or Google Cloud
• Experience with identity and access management, SSO, MFA, RBAC, and privileged-access controls
• Experience deploying and maintaining security technologies, including SIEM, EDR, vulnerability-management, secrets-management, and intrusion-detection tools
• Experience with Linux administration, system hardening, patch management, and configuration management
• Experience investigating security incidents, reviewing logs, identifying root causes, and implementing remediation
• Educated to degree level or equivalent experience (preferably in computing)
• CISSP, CCSP, or Security+ an advantage but not necessary

• Strong team player
• Clear communication
• Troubleshooting mindset
• Networking fundamentals (TCP/IP, DNS, firewalls, VPNs, proxies, load balancers)
• Infrastructure-as-code and automation (Terraform, Ansible, Python, Bash)
• Containers and orchestration (Docker, Kubernetes)