Senior Platform Engineer (United Kingdom)

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 flo…