Software Developer In Test / Automation tester

Senior Software Developer in Test / Automation Tester£60,000 – £70,000 + bonus Office-based / South West londonWhat happens when software can't simply be taken offline, patched and restarted when something goes wrong?That’s the environment this team is building for.We’re working with a growing technology company developing software that helps protect and manage the industrial systems behind some of the UK’s essential infrastructure.Their technology is already deployed within organisations operating across a significant proportion of the UK’s critical infrastructure, and with the business continuing to grow into new customers and regulated markets, they’re now looking for a Senior Software Developer in Test / Automation Tester to take real ownership of how their platform is tested.This isn't a role where you'll inherit a test suite and spend your time pressing run.You'll be expected to understand how the platform works, where it's most likely to fail, and then build the testing, automation and processes that give the engineering team confidence in what they're shipping.The roleYou'll take ownership of software testing across a distributed platform built predominantly in Go and made up of multiple interconnected services.Working directly alongside the software engineers, you'll turn system and user requirements into meaningful test coverage, designing system, integration and automated tests that exercise the product as a whole.A big part of the role will be building and improving automation from scratch. You'll decide what should be automated, create repeatable tests and make sure they're properly integrated into the development and CI/CD process.You'll also get underneath failures when they happen. Rather than simply raising a ticket, you'll investigate the issue, isolate what's going wrong and work with the developers to understand the root cause.The environment combines software with physical edge devices, so testing isn't limited to a browser or API. You'll have access to an on-site lab where you can test how the platform behaves when interacting with the real devices and environments it's designed to support.Over time, you'll effectively become a guardian of the product, understanding where the risks and gaps are and continuously improving the team's approach to quality.What we're looking forWe're open to people coming from Software Developer in Test, SDET, Automation Test Engineer or senior technical QA backgrounds.The important thing is that you've previously taken ownership of testing for a complex software product and you're comfortable creating automation rather than simply maintaining what someone else has built.You'll need strong experience with system and integration testing, including API testing, alongside the scripting or programming ability to automate those tests effectively.You'll understand how to take requirements and turn them into clear test specifications, coverage and acceptance criteria, while still having the curiosity to look beyond the happy path and find the edge cases nobody has considered.Experience with tools such as Playwright or equivalent automation frameworks, along with CI/CD and GitHub Actions, would fit particularly well. Some experience with Docker, Docker Compose or containerised test environments would also be valuable.The platform is largely written in Go (Golang), but you don't need to be a Go developer. If you've worked with Go before, great. If not, being comfortable reading code and understanding how services interact is more important.Experience testing microservices or distributed systems would also be useful, particularly if you're familiar with the less obvious ways those systems can fail.More than just running testsThe team is specifically looking for someone proactive.You'll work closely with developers, product and systems engineers, so you'll need to be comfortable asking questions, challenging assumptions and communicating when you see a risk.If a requirement doesn't quite make sense, you'll question it.If you spot an edge case, you'll investigate it.If the current testing approach could be better, you'll be encouraged to change it.You'll also have the opportunity to influence the wider test strategy, CI/CD pipeline, test environments and approach to areas such as vulnerability scanning as the platform continues to evolve.Why join?The business has been established for around five years and is approaching 20 people, with hiring being driven by growth rather than replacement.Its technology is already being used within UK critical infrastructure, and the company is continuing to onboard customers while exploring opportunities across other regulated industries.That creates an interesting challenge for a senior tester. The product is established and being used in environments where reliability matters, but the team is still small enough that one person can have a significant influence over how quality engineering is done.You'll work directly with the people building the platform, have ownership rather than being buried inside a large QA function, and have the freedom to introduce better tooling, automation and ways of working.There’s a £60,000 – £70,000 salary, alongside bonus potential and opportunities for professional development.You'll need to be comfortable being in the office five days a week initially. There’s a genuine reason for that: the role involves working with the team's physical lab and edge devices, as well as collaborating closely with the engineers while you get up to speed.Once you're established, there is potential for one or two days working from home, depending on the needs of the role.If you're the type of tester who gets satisfaction from finding the failure mode before the customer does, and you'd rather build the testing strategy than simply inherit one, this could be a very good fit.