Secure Developer

Secure Developer (Linux / Container Hardening) Hybrid / UK-Based Competitive Day Rate / Salary Security Clearance Required (SC or higher preferred) Overview We are seeking a Secure Developer to design and implement advanced endpoint and runtime protection controls for critical software environments. This role focuses on Linux hardening, container security, and low-level system telemetry, helping reduce risk across core application and infrastructure layers. You will work at the intersection of systems engineering, security, and DevSecOps, building robust protections directly into Ubuntu hosts and Docker environments, and integrating security telemetry into early-stage SIEM and detection pipelines. This is a hands-on engineering role requiring deep understanding of Linux internals, container runtimes, and security hardening standards. Key Responsibilities • Harden Ubuntu Linux hosts at kernel and OS level using: • sysctl tuning • namespaces • AppArmor • seccomp • Linux capabilities • Implement and maintain auditd rules, syscall-level logging, and host/container telemetry for detection, monitoring, and forensic analysis • Apply and enforce CIS Benchmarks (Level 2) for: • Ubuntu Linux • Docker containers and runtime environments • Hardened base image standards and secure configuration baselines • Secure Docker runtime environments through: • least-privilege execution models • container isolation strategies • image provenance and signing • Docker daemon hardening • Develop EDR-style capabilities using: • kernel-level telemetry • runtime behaviour monitoring • host-based detection logic • Integrate host and container logs into prototype SIEM pipelines, enabling correlation and early threat detection • Automate security controls, hardening processes, and compliance checks using: • scripting (Python / Bash) • infrastructure-as-code tools (Terraform / Ansible preferred) Required Experience • Strong experience with Linux systems engineering (Ubuntu preferred) • Deep understanding of Linux kernel security controls and namespaces • Hands-on experience with Docker container security and runtime hardening • Experience implementing auditd, syscall monitoring, or host-based telemetry systems • Familiarity with CIS Benchmarks and secure configuration management • Strong scripting ability (Python, Bash, or similar) • Experience with infrastructure automation tools (Ansible, Terraform, or similar) • Understanding of endpoint security, runtime security, or EDR concepts Desirable Experience • Experience building or integrating SIEM solutions or security pipelines • Knowledge of eBPF-based monitoring or kernel instrumentation • Exposure to Kubernetes security hardening (optional but beneficial) • Experience in secure software development or DevSecOps environments • Familiarity with cloud security controls (AWS / Azure / GCP) • Experience working in defence, government, or highly regulated environments Clearance Requirement Applicants must hold active UK SC Clearance (or higher) due to the sensitive nature of the environment. What’s on Offer • Opportunity to build real-world endpoint security and runtime protection systems • Work on low-level Linux security engineering and container hardening • High-impact role improving resilience of core enterprise software • Exposure to advanced security engineering and prototype SIEM development • Collaborative engineering environment focused on security-by-design