Senior Software Engineer in Test (Security) in Richmond

About us

Securing Critical National Infrastructure is one of the most consequential engineering challenges of the next decade, and in OT environments, where systems can't simply be patched or taken offline, quality isn't a nice‑to‑have. It's everything. At the company, our flagship product Phoenix protects the industrial control systems behind essential services, and our customers trust it precisely because of the rigour behind what we ship. We're now looking for someone to own software testing end‑to‑end.

Why join us?

• Meaningful work — your testing is the reason the systems behind energy, water and manufacturing stay secure
• Real ownership — you'll define and drive test strategy across Phoenix, end‑to‑end, treating it as engineering rather than an afterthought
• A collaborative, close‑knit team — ideas are heard, and you'll work directly alongside the engineers building the platform
• Room to grow — we're scaling fast, and there's genuine opportunity to shape both the product and your own career

If you take satisfaction in finding the failure mode before a customer does, this is the role.

About the Role

You'll own software testing end‑to‑end for Phoenix, our high‑level platform built mostly in Go across a distributed, microservice architecture. That means understanding the system from both the requirements and the user's point of view, then turning that understanding into test specs, system tests, and integration tests that give us real confidence in what we ship. This is a hands‑on senior role for someone who treats test strategy as engineering – not an afterthought – and who enjoys finding the failure mode before a customer does. You don't need to be a Go developer, but you'll be more effective if you can read the code, understand how the services fit together, and reason about where things are likely to break.

What will you do

• Write clear, thorough test specifications and plans derived from system and user requirements, with defined coverage, acceptance criteria, and traceability back to what the software is meant to do.
• Plan and run system tests that validate Phoenix as a whole against its requirements, documenting outcomes and communicating results in a way the team can act on.
• Plan, design, and run integration tests that exercise the interfaces between services using API testing tools, writing scripts to automate and repeat those tests reliably.
• Debug issues and work with developers to pinpoint root causes – investigating failures, isolating the cause, and partnering with the dev team to identify areas of potential risk before they become defects.
• Take ownership of all software testing for Phoenix, keeping the test landscape healthy and knowing where the risks and gaps are.
• Build and maintain the CI/CD pipeline, keeping automated builds, tests, and deployments reliable as the platform evolves.
• Look after vulnerability scanning and reporting, running scans periodically and reporting findings so risks are visible and addressed.
• Innovate and improve our test strategy, bringing new approaches, tooling, and automation that raise coverage and confidence as Phoenix grows.

What we're looking for (essential)

• Proven experience as a senior software test engineer, owning testing for a non‑trivial software product.
• Ability to understand system requirements and user requirements and derive test coverage from them.
• Strong track record writing test specs and plans, and running system and integration tests.
• Hands‑on with API and integration testing tools, and comfortable writing scripts to automate test execution.
• Strong debugging and problem‑solving skills, and the ability to assist the dev team in identifying areas of potential issues before they surface.
• Excellent attention to detail – you notice the edge case, the off‑by‑one, the requirement that doesn't quite add up.
• Ability to work effectively in a multidisciplinary team alongside developers, product, and systems engineers.
• A drive to innovate test strategies rather than run the same suite forever.
• Experience with test automation frameworks, CI pipelines, or containerised test environments (e.g. Docker).

Nice to have

• A basic understanding of Go (Golang) – enough to read the codebase and reason about behaviour.
• Familiarity with microservice architecture and the failure modes that come with distributed systems.
• An understanding of Docker Compose.

What We Offer

• Highly competitive salary tailored for experienced technical leaders, plus performance and yearly bonuses.
• Genuine technical ownership of groundbreaking technology with direct impact on industrial security.
• Access to professional development opportunities and conferences.
• A dynamic, collaborative culture that encourages innovation.

Join the company and lead the charge in building innovative, secure solutions for industrial control systems.

Job Type: Full‑time

Pay: £55,000.00‑£70,000.00 per year

Education: Bachelor's (preferred)

Experience: Software testing: 5 years (required)

Work authorisation: United Kingdom (preferred)

Willingness to travel: 75% (preferred)

Work Location: In person