Location
Central London

Hours
Full Time

Salary
£66,332 per annum

About the Role
MI5 keeps the country safe from serious threats like terrorism and attempts by states to harm the UK, its people, and way of life. We carry out investigations by obtaining, analysing, and assessing intelligence, and work with partners including MI6 and GCHQ to disrupt these threats. Through our protective security arm, we provide advice and guidance to government, businesses, and other organisations on how to keep themselves safe. A role in MI5 means you'll do unique and challenging work in a supportive and encouraging environment, making a real difference to UK national security.

As a Platform Engineer, you'll design, develop and operate platforms that give developers the tools they need to build critical technology that helps keep the country safe. You will contribute to a growing technology capability and be part of an expanding engineering workforce, enhancing platforms and products delivered across the organisation.

Day to day, the role involves building developer tooling, managed services, automation, and self-service solutions. Infrastructure-as-code is used to ensure consistency and reliability across cloud and on-premises environments, enabling teams to move quickly with confidence.

A significant part of the role centres on working closely with product teams to understand pain points, prioritise what matters most, and shape solutions that improve the developer experience. The outcome is streamlined workflows, reduced friction, and more time for engineers to focus on delivering solutions to meet MI5’s outcomes. You’ll play a key part in contributing to our engineering community by sharing best practice standards, patterns, and establishing clear and consistent approaches that teams can adopt with confidence.

When issues arise, you’ll troubleshoot platform problems and improve reliability, usability, and observability, feeding insights back into better design. Sharing knowledge across teams and helping to build a consistent, collaborative engineering culture is essential. You’ll also support other engineers, helping them build confidence and develop their skills.

Platform engineering evolves constantly, so there is regular protected time to horizon scan, research emerging trends, and pursue training or certifications relevant to your career.

Benefits
Starting salary of £66,332 plus benefits including:
- 25 days’ annual leave rising to 30 days after 5 years’ service, plus 10.5 days of public and privilege holidays
- Employee performance recognition scheme
- Dedicated development budget
- Interest-free season ticket loan
- Excellent pension scheme
- Cycle to work scheme
- Facilities such as subsidised gym, restaurant, and on-site coffee bars (at some locations)
- Paid parental and adoption leave

Experience
Experience as a Platform or DevOps Engineer across a range of technologies and customer environments, or a Software Engineering background with demonstrable experience solving platform and infrastructure-related challenges. Familiarity with infrastructure-as-code tools such as Terraform is important.

About you
A natural problem solver who enjoys tackling complex challenges and turning them into practical solutions. You understand the software development lifecycle in enterprise or commercial environments and are familiar with design patterns and secure coding practices. You work closely with engineers and technologists, communicating confidently with both technical and non-technical audiences to explain ideas clearly, align priorities, and build trust across teams. You are comfortable working independently with a high level of autonomy, making pragmatic decisions and seeing work through from problem to solution. You are proactive in seeking support when needed and have a strong willingness to learn and grow.

Qualifications
Proficiency in at least one modern programming language such as Node.js, Python, or Java. Experience with core engineering practices including test-driven development (TDD), continuous integration/continuous delivery (CI/CD) pipelines, cloud services, and agile methodologies is expected.