Senior Platform Engineer (United Kingdom) in London

Second Front Systems (2F) is seeking an ambitious and capable Platform Engineer to join our UK team. We are a dynamic, fast-growing defence technology company at the intersection of cutting-edge technology and national security, committed to delivering transformative solutions that empower the UK’s defenders. This is an opportunity to play a pivotal role in establishing and scaling our platform capability in the UK market.

At 2F we thrive on innovation and purpose, combining a start-up’s agility with a clear mission to support national security. You will be at the forefront of the DevSecOps engineering behind the deployment and scaling of our Game Warden platform — accelerating the secure adoption of mission-critical SaaS solutions for UK government and defence. If you value ingenuity, collaboration, and impact, we want to hear from you.

Security Clearance Requirement: This position requires the holder to hold, or be eligible to obtain, Developed Vetting (DV) clearance. Candidates must be UK nationals (or hold dual nationality with the UK as one nationality) and have sufficient UK residency history to be sponsored for DV. Active DV clearance is strongly preferred. As this role involves work within classified and air-gapped environments, clearance eligibility is essential and non-negotiable.

Location: Primarily remote (UK-based), with frequent travel to customer and partner sites, including Northwood and Corsham Defence Campus, and occasional travel to other UK government locations. Candidates must be based within the UK and willing to travel as operational demand requires. Note that work in air-gapped or classified environments will require on-site presence at accredited facilities.

What You'll Do:

• Architect and implement scalable, secure cloud infrastructure using Kubernetes and Pulumi (Go-based), ensuring compliance with UK government and Ministry of Defence security requirements.
• Support the security and operations of Game Warden across air-gapped and classified environments, working directly with government partners and security teams.
• Build and manage CI/CD pipelines that integrate DevSecOps best practices from development through to deployment.
• Integrate and maintain SIEM and security tooling, ensuring observability and compliance across all deployed systems.
• Design, develop, and debug microservices in Go (Golang), with a focus on performance, security, and modularity.
• Work cross-functionally to assess infrastructure needs, prioritise development, and deliver on product roadmap milestones in a fast-paced Agile environment.
• Document your work thoroughly — from infrastructure to internal procedures — to ensure secure, repeatable, and auditable deployments.
• Collaborate directly with UK defence and government stakeholders to provision secure cloud resources and meet deployment and accreditation criteria in classified settings.
• Contribute to R&D and experimentation needed to advance platform capabilities in secure and disconnected environments.
• Act as a senior technical resource, helping to shape 2F’s UK DevSecOps strategy and infrastructure standards.

What You Bring:

• 5–7+ years of relevant experience in DevSecOps, systems engineering, or infrastructure software development.
• Architect-level expertise designing and operating cloud-native platforms using AWS, Azure, or GCP.
• Deep experience with Kubernetes, Docker, and cloud-native application orchestration.
• Strong proficiency in Golang or similar languages (e.g. Rust), particularly with infrastructure as code (Pulumi preferred).
• Familiarity with UK and international compliance frameworks such as MOD Secure by Design, JSP 453, NCSC Cloud Security Principles, NIST 800-53.
• Proven experience deploying systems in air-gapped or classified environments.
• Experience building and maintaining secure CI/CD pipelines and integrating security throughout the SDLC.
• Hands-on experience implementing or managing SIEM, monitoring, and alerting systems.
• Understanding of REST APIs, authentication flows, event-driven architecture, and microservice patterns.
• Excellent written and verbal communication skills, with strong documentation habits.
• Comfortable working independently and in distributed teams, managing competing priorities across complex projects.
• Proficient in using AI tools (such as Claude and Gemini) to accelerate and enhance day-to-day work, from code generation, debugging, and documentation to research and problem-solving — with sound judgement about where AI adds value and where human oversight is required.
• Certified AWS, Google or Azure Solutions Architect.
• Prior experience working within UK defence, national security, or regulated government environments.
• Experience working in early-stage or high-growth start-up environments.
• Familiarity with UK accreditation and risk-management processes and environments (e.g., MOD Secure by Design).
• Familiarity with GitLab, Google Workspace, and Slack.
• A genuine interest in national security and mission-driven innovation.

The base salary for this position will fall between £100,000 - £115,000. Your ultimate compensation will be determined by professional background, technical proficiency, seniority, and regional cost factors. Furthermore, this opportunity includes potential eligibility for equity awards and discretionary bonuses, rounding out a comprehensive total rewards offering.

Success at 2F Looks Like:

• Viewing obstacles as opportunities for growth
• Having a bias toward action and tangible, measurable results
• Striving to be both compassionate and direct with your feedback
• Being team-oriented and inclusive with your actions

Perks & Benefits:

• Competitive salary benchmarked to UK market
• Private healthcare (medical, dental, and optical)
• Pension scheme with employer contribution
• Wellness perks (fitness, mental health resources)
• Equity incentive plan
• Technology and home-office stipend
• Annual professional development budget
• Flexible paid time off plus UK public holidays
• Enhanced parental leave
• Remote-first working with travel expenses covered
• Referral bonus scheme

Second Front Systems is an equal opportunities employer. We are committed to building a diverse and inclusive team and welcome applications regardless of age, disability, gender reassignment, marriage and civil partnership status, pregnancy and maternity, race, religion or belief, sex, or sexual orientation, in accordance with the Equality Act 2010.

Applicants have the right to work in the United Kingdom. Due to the DV clearance requirement, candidates must be UK nationals or hold qualifying dual nationality and must have resided primarily in the UK for the period required by UKSV vetting guidelines. Sponsorship for this role is not available.

This role is a full-time permanent position. Salary will be discussed during the recruitment process. We are happy to discuss reasonable adjustments at any stage of the application process for candidates with a disability or long-term health condition.

At Second Front Systems (2F), we equip defence and national security professionals with access to emerging technologies. Founded with firsthand experience of the dangers that outdated technology poses in operational environments, our team is dedicated to fast-tracking government access to disruptive, commercially-proven technology for national security missions.

Our Game Warden platform is a fully managed and compliant DevSecOps environment that accelerates the accreditation and deployment of SaaS applications for government use. Learn more at www.secondfront.com.

To apply, click the “Apply for This Job” button at the top or bottom of this page and complete the application form. This position will remain open until filled, and applications will be reviewed on a rolling basis.