Senior Infrastructure Field Engineer

Department Technology Roles

Location(s) Central London

£53,267 to £62,599, depending on skills and accreditation

Central London, with travel to other UK locations expected on a weekly basis

This role qualifies for a specialist capability-based pay approach, which recognises and rewards cyber technical expertise. Based on an assessment of skills and experience at interview, candidates may be eligible for an additional skills payment, potentially increasing the salary to £62,599.

To retain the higher salary, individuals will need to demonstrate and accredit their skills against our Cyber Technical Framework within the first years of employment. If the required skills cannot be evidenced initially, support and an opportunity to address any gaps will be provided. If this is not achieved by the end of the first year, it may result in a return to the lower end of the stated pay range.

As skills develop and are maintained, there will be opportunities to progress further within the pay range at this grade. Employees can apply for recognition of increased skills levels at regular intervals, in agreement with their line manager.

This role is primarily office‑based due to the nature of the work. Flexible working arrangements are supported, including flexitime with flexible start and finish times, as well as the option to work compressed hours.

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.

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…