Senior Software and Security Engineer

Salary: £83,000 - 95,000 per year

Requirements:

• Several years hands-on engineering experience delivering complex technical and security work independently and to a high standard.
• Proven ability to review, critique and constructively challenge technical work produced by others.
• Strong working knowledge across networking, Linux, architectural security, infrastructure as code, containers and cloud platforms.
• Software development ability in at least one language, with the judgement to assess system-level impact of code produced by others.
• Clear technical communication skills, including the ability to engage credibly with customers, regulators and senior stakeholders.
• A degree in Computer Science, Software Engineering, Network Engineering, Cybersecurity or a related STEM discipline, or equivalent capability demonstrated through substantial industry, project-based or self-directed experience.
• Professional-level certifications such as CISSP, cloud security, professional-level cloud or ISC2 certifications.
• Experience in OT/ICS security, regulated industries or Critical National Infrastructure environments.
• Applied experience of NIS2, NCSC CAF, IEC 62443, OT/ICS protocols or architecture, or mentoring junior engineers.

Responsibilities:

• Lead the evaluation and proving of new technology before delivery, including software development for proofs of concept, demonstrators and structured technical assessments.
• Iterate customer technical and security commitments into practical controls, configuration, software changes and mitigations for the systems you own.
• Provide independent technical challenge to Development and Assurance, reviewing source code, infrastructure-as-code and architecture against requirements and good practice.
• Front direct technical engagement with customers, regulators and industry bodies for owned systems and areas, preparing materials and evidence that stand up to scrutiny.
• Design, implement and maintain architectural controls across our AWS based systems, identifying, remediating and evidencing security and resilience issues across the business.
• Oversee and review work produced by Graduate Engineers and Engineers, giving constructive, standards-based feedback that raises the technical bar.
• Deepen your primary technical specialism while building cross-functional awareness across OT cybersecurity, cloud security, assurance and UK Critical National Infrastructure.

Technologies:

• AWS
• Cloud
• EC2
• Linux
• MacBook
• Network
• Security

More:

We are deltaflare, the UKs specialist in Operational Technology (OT) cybersecurity for Critical National Infrastructure operators. We deliver NIS2 and CAF compliant protection across gas, electricity, water, renewable technology and transport networks, helping secure the systems that keep the country running. We work where IT meets industrial reality, inside control rooms, substations and treatment works, supporting operators without disrupting essential services. Our mission is to enable the safe and cyber secure operation of hyper-connected industrial systems, and our vision is a world where essential services can deliver digital transformation with confidence. We value integrity, innovation, openness and being mission driven. This Senior Software Engineer role sits within our Technology team, works mostly independently under the Head of Technology, and includes a salary of £83,000 to £95,000 per year, 25 days annual leave plus bank holidays, employer contributed pension, regular team and industry events, and a personal EC2-based Linux development environment with an Apple MacBook for daily work. The role is in person in London, Greater London.

last updated 36 week of 2026