Senior Platform Engineer

Work on Technology That Protects What Matters

At SiXworks, we build secure digital solutions that support Defence and National Security missions. Our teams work on complex problems where reliability, security, and speed of innovation matter.

We’re looking for a Senior Platform Engineer who enjoys solving difficult technical challenges and wants their work to have real operational impact.

What You’ll Do

As a Senior Platform Engineer, you’ll lead the design and implementation of CI/CD pipelines, Kubernetes configuration, monitoring systems, repository management, automation, and other critical platform components. Collaborating closely with the Platform team, the Platform Engineer will ensure seamless integration of our offerings with the development team's requirements. While the role may encompass a broad scope, including deployment automation and CI/CD pipeline configuration initially, it will gradually shift towards supporting the platform's maintainability, supportability, security, and scalability/performance.

Your work may include:

• Configure Kubernetes environments to support scalable and resilient application deployments.
• Lead the design and construction of CI/CD pipelines to streamline the deployment process and enhance development efficiency.
• Support both on-premise and cloud platforms, ensuring consistency, reliability and maintainability through automation and Infrastructure as Code.
• Implement robust monitoring solutions to ensure the health and performance of platform services.
• Manage repository systems and version control to facilitate collaboration and code management.
• Drive automation initiatives to optimise workflow processes and reduce manual intervention.
• Collaborate with the Platform team to ensure alignment between platform capabilities and development team requirements.
• Mentor engineers within the team, review designs and code, and raise the overall standard of the platform engineering practice.
• Provide guidance and oversight to the development team on best practices for utilising platform offerings effectively.
• Support initiatives related to platform maintainability, supportability, security, and scalability/performance as the platform evolves.
• Monitor industry trends and emerging technologies to continually enhance platform capabilities and practices.

What We’re Looking For

We value people who take ownership, think critically, and enjoy working as part of a collaborative team tackling complex challenges. You don’t need to tick every box, but we’re particularly interested in people with skills/experience in:

• Bachelor's degree in Computer Science, Engineering, a related field or equivalent experience
• 5+ years of experience in Platform Engineering, Site Reliability Engineering, Platform Integration, or related roles.
• Strong production experience with Kubernetes (ideally AKS) and container orchestration techniques.
• Experience with GitOps and CI/CD tooling (e.g Flux or Argo CD, GitHub Actions or equivalent)
• Strong understanding of Infrastructure as Code practices and tooling such as Terraform.
• A security-first mindset and experience working within least privilege, private-by-default, or otherwise constrained environments.
• Experience with monitoring tools such as Prometheus, Grafana, or similar for infrastructure and application monitoring.
• Solid understanding of version control systems, preferably Git, and repository management practices.
• Proven track record of driving automation initiatives to improve operational efficiency and reliability.
• Excellent communication and collaboration skills, with the ability to interact effectively with cross-functional teams.
• Strong problem-solving skills and the ability to thrive in a fast-paced, dynamic environment.
• Experience with cloud platforms (ideally Azure).

Just as important are curiosity, strong problem solving ability, and the motivation to continuously improve how technology is designed and delivered.

About SiXworks

SiXworks is a specialist digital innovation partner delivering secure, mission-critical technology to Defence and National Security organisations. We focus on digital experimentation, secure-by-design architecture, cloud technologies, and rapid application development to help our customers move faster and stay ahead of evolving challenges.

Our team combines expertise from across technology, business, and operational backgrounds including the armed forces creating a collaborative environment where practical thinking and innovation thrive.

Why Join Us

Our culture is guided by six principles: Agility, Security, Innovation, Quality, Collaboration and Inclusivity our North Star for how we work. SiXworks is a leading provider of secure digital solutions, specialising in digital experimentation and focused on fail-safe-fast cutting-edge technology solutions deployed in highly secure environments.

As an end-to-end digital innovation and delivery partner, we turn complex challenges into mission-critical digital advantages. This is a thrilling time for us, with ambitious plans for growth. We are looking for brilliant, experienced, driven and self-motivated people to join the team on our journey.

We offer competitive salaries and a package that supports your wellbeing and development, including 25 days annual leave + bank holidays, free Private Medical cover and Life Assurance, Generous pension (10% employer, 5% employee contribution), Bonus and Professional development and training support. In addition to secure parking, gym, café & restaurant on site and lots of open break out spaces.

A word on UK Security Clearance

Due to the secure nature of the position and working environment, you must have or be eligible to obtain Security Clearance. More details relating to UK Security Clearance can be found here:

United Kingdom Security Vetting: clearance levels - GOV.UK (

Interested?

Please apply!