Senior Infrastructure Field Engineer (MI5)

While no specific qualifications are required for this role, you will already have extensive experience working in network engineering within a technical industry environment. You’ll bring a solid foundation in designing network solutions, with the confidence to operate across large-scale, mission critical infrastructure. In particular, you’ll be able to demonstrate expertise in several of the following areas:

• Network design, architecture and transmission technologies, supporting resilient and high-performance network solutions
• Layer 2 and Layer 3 technologies, including protocols, MAC and IP addressing, BGP and VPNs
• Fibre optic networking, with practical experience of wavelengths, multiplexing (MUX), transponders and long‑haul transmission technologies
• Automation, scripting and systems administration, including use of GNU/Linux operating systems at the command line, automation tools such as Ansible, and at least one scripting or programming language (for example, Bash or Python)

Alongside this, you’ll have practical experience configuring and managing network devices within live environments, applying changes safely and effectively, and supporting the ongoing operation and evolution of complex network infrastructures. Importantly, you’ll have a genuine interest in cyber and global datacentre interconnection and a desire to bring your enthusiasm to a new environment. You might already have industry accreditations such as from Red Hat, Arista, Juniper, Cisco; if not, we’ll support you in gaining these once in the role. A commitment to ongoing learning and professional development is essential.

As someone comfortable working on projects within cross‑functional teams, you’ll demonstrate proven problem‑solving skills and the ability to clearly communicate internet infrastructure concepts to both technical and non‑technical audiences. Given the collaborative nature of the role, you’ll be an effective and confident communicator, able to build good working relationships with colleagues, customers, partners, and stakeholders at all levels. You’ll need to meet the physical requirements of the role, which may include lifting, carrying, and moving equipment. Please note that a fitness assessment will be conducted by occupational health as part of the application process.

If you enjoy tackling complex technical challenges that genuinely make a difference, this role offers the opportunity to see the impact of your work every day. As a Senior Infrastructure Field Engineer, you’ll be part of a specialist team responsible for designing, installing and maintaining the intelligence‑gathering solutions we rely on. Leading a core workstream, you’ll support multiple mission areas across MI5, MI6 and GCHQ, delivering bespoke solutions for a range of high‑priority requirements. Whether you’re enabling data retrieval from large, intricate networks or building relationships across the organisation, you’ll help drive an expanding remit and play a vital role in keeping the UK safe.

Day‑to‑day, the role involves designing, installing, configuring and managing remote infrastructure such as firewalls, routers, switches and servers as well as investigating technical issues. Close collaboration with internal stakeholders is required to understand and meet their unique requirements. Responsibilities include contributing to the development and implementation of automation systems and supporting the administration of the multi‑vendor environment. Opportunities are also available to undertake individual project work in relevant technical areas, subject to alignment with the team’s work and priorities.

Upon completion of all relevant training, you’ll also have the opportunity to join our on‑call rota. Participation is optional, and for the majority of the time, work outside of core hours is voluntary. On the rare occasion that the team is short‑staffed, you may be required to act as cover. The role also offers a unique opportunity to work with colleagues in industry, often at the cutting edge of networking technologies. There may also be opportunities to attend international events, such as conferences, once or twice a year.

This role attracts specialist capability‑based pay in recognition of cyber technical expertise. Based on skills and experience assessed at interview, appointment may be made at a higher salary point within the stated range. Retention of any higher salary is subject to demonstrating and accrediting the required skills against the Cyber Technical Framework within the first year of employment. Support will be provided to achieve this. As skills develop, there are opportunities to progress further within the pay range.