Software Security Engineer

Software Security Engineer – Defence & Government SystemsLocation: El Segundo, California (onsite)Contract: 12 months, with potential extensionsRate: $75–$85 per hourExperience: 5+ yearsThe OpportunityWe’re seeking an experienced Software Security Engineer to support a defence-focused programme in El Segundo, California. This is a 12-month contract with the potential for extension, offering the opportunity to work at the intersection of software engineering, cybersecurity and mission-critical government systems.You’ll help ensure security is embedded throughout the software development lifecycle, supporting secure architecture, API design, systems integration and compliance with relevant Department of Defense (DoD) cybersecurity requirements.Working closely with software, systems engineering and cybersecurity teams, as well as government stakeholders and prime contractors, you’ll help identify risks, develop practical security recommendations and support the delivery of secure, resilient software solutions.Key ResponsibilitiesSupport secure software development lifecycle (SSDLC) practices and ensure security requirements are incorporated from the early design stages.Assess software architectures, microservices, APIs and data interfaces for security risks and vulnerabilities.Support DoD cybersecurity processes, including Risk Management Framework (RMF) activities and the preparation of technical artefacts supporting Authority to Operate (ATO) requirements, as applicable.Collaborate with software developers, systems engineers, cybersecurity teams, government stakeholders and prime contractors to align security requirements and delivery priorities.Identify and communicate technical risks, mitigation strategies and implementation options to both technical and non-technical stakeholders.Contribute to secure deployment strategies, vulnerability management and compliance with relevant security controls.Manage competing priorities while supporting delivery in a regulated, mission-critical environment.Produce clear technical documentation, recommendations and briefings.Required Experience & Skills5+ years of relevant professional experience in software security, systems engineering, cybersecurity or a related technical field.Strong understanding of secure software development lifecycles and secure design principles.Experience with service-oriented architectures, microservices, secure API design and data interface assessments.Familiarity with DoD cybersecurity processes, including RMF and ATO-supporting technical documentation, where applicable.Proven ability to work across software, systems engineering and cybersecurity teams.Experience aligning technical requirements and priorities across government stakeholders and prime contractors.Strong written and verbal communication skills, including the ability to explain security risks and recommendations clearly.Ability to manage competing priorities in regulated or mission-driven environments.Proficiency in Microsoft Office, including Word, Excel and PowerPoint.Desirable ExperienceActive Secret security clearance or higher.Experience deploying or supporting software on DoD networks, in classified environments or across mission-critical systems.Familiarity with DoD-aligned DevSecOps frameworks and practices.Knowledge of Security Technical Implementation Guides (STIGs), security controls and vulnerability management tools.Experience with Docker, Kubernetes and containerised deployments, including disconnected or restricted networks.Exposure to AWS GovCloud and/or Microsoft Azure Government.Familiarity with Jira and Confluence in Agile delivery environments.Experience implementing Agile methodologies within government or defence programmes.Background in systems integration, Interface Control Documents (ICDs) or system-of-systems engineering.Relevant certifications, such as CSEP, ESEP, PMI or PMP.Interested?If you have experience supporting secure software delivery in complex, regulated or defence environments and are looking for your next contract opportunity, we’d like to hear from you.Please apply with your latest CV by October 22, 2026.