Software Development Engineer in Test (SDET) – Unity in Stafford, England at Strolll ltd

About Strolll

🎯Core purpose:

Strolll exists to give people a new reality; that inspires them to believe in limitless human potential to overcome their most difficult rehabilitation challenges.

🚀 Mission:

Strolll is transforming the world of rehabilitation and physical therapy with its state-of-the-art software platform for augmented reality (AR) glasses; with a focus on individuals living with neurological disorders, such as Parkinson's disease, stroke and MS.

♟️ Objective:

Become the most used rehabilitation software in the world.

📈 Key Result:

7 million weekly rehab minutes by NYE 2029.

About the roleAs a Software Development Engineer in Test (SDET), you will be responsible for ensuring the quality, reliability, and performance of Strolll's Unity-based Augmented Reality applications through a combination of automated and manual testing.

You will design and maintain automated test frameworks — including bespoke test harnesses and tooling where off-the-shelf simulation isn't sufficient — execute manual testing where required, and work closely with Engineering, Product, Clinical, Regulatory, and Customer Success teams to ensure high-quality releases. You will act as a technical bridge between our Unity development team and QA, surfacing low-level implementation detail in ways that make the application testable, and you will help embed quality — and modern, AI-assisted ways of working — throughout the development lifecycle.

Reporting to the Principal QA Engineer, you will play a key role in expanding test automation coverage, improving testing practices, and supporting Strolll's mission to become the most used rehabilitation software in the world.

Roles and responsibilities

Test Automation for Strolll's Augmented Reality Applications

Design, develop, and maintain automated test frameworks for Unity applications.Create and execute Play Mode and Edit Mode tests using the Unity Test Framework and develop extensions where necessary.Build bespoke test tooling and harnesses for scenarios where Unity's built-in simulation capabilities are unreliable or give false confidence.Extend automated testing beyond the Unity client itself — including data integrity and integration testing for connected systems such as our CMS (Content Management System), cloud-hosted services and APIs.Develop automated functional, integration, regression, and end-to-end tests.Monitor and validate application performance, memory usage, and stability across supported devices.Integrate automated testing into CI/CD pipelines.Analyse test results and investigate failures.

Manual Testing & Quality Assurance

Proactively look for ways to make manual testing faster and more reliable — e.g. using capture, instrumentation, and AI-assisted tooling to streamline execution and the recording of results and defects, particularly in hard-to-automate areas such as real-device XR, rather than treating hands-on testing as a fixed overhead.Execute test cases where automation is not yet built out or suited to automation (e.g. real-device spatial/AR interactions).Validate application functionality, user workflows, UI behaviour, and overall user experience.Reproduce, document, and verify defects.Support release validation and user acceptance testing activities.

Collaboration & Continuous Improvement

Act as a technical bridge between Unity developers and the QA function — working with developers to expose low-level implementation detail (state, internals, hooks) that is currently invisible from outside the application, so that QA can meaningfully test against it.Champion QA involvement upstream in the design process — engaging early enough to call out testability and quality risks before they're built in, rather than discovering them at test time.Help shape user stories and acceptance criteria so QA-relevant information is present by the time work enters delivery — e.g. edge cases, testability constraints, and non-functional considerations captured as stories are written, not retrofitted afterwards.Review requirements and acceptance criteria to ensure they are testable and complete.Participate in Agile ceremonies including sprint planning, reviews, and retrospectives.Contribute to test plans, quality standards, and testing best practices.Continuously improve automation coverage, testing processes, and quality reporting.

Championing AI-Assisted Quality Practices

Actively champion the adoption of AI tooling within QA and testing workflows — identifying where AI can meaningfully accelerate test generation, test maintenance, defect triage, or reporting, and driving adoption of these practices across the wider QA/engineering team rather than treating this as a one-off initiative.

Qualifications and skills

Essential

3+ years' experience in a Software Testing, QA Automation, or SDET role.Strong C# development skills with experience designing, building, and maintaining automated test frameworks using C# and modern testing practices.Strong hands-on experience developing or testing applications in Unity, including use of the Unity Test Framework, Play Mode testing, and Edit Mode testing.Demonstrated ability to build custom test tooling or simulation/harness solutions from scratch — not just configure existing frameworks — particularly for scenarios where standard simulators or test doubles don't reflect real-world behaviour.Knowledge of Unity performance and memory profiling.Experience using Jira, Azure DevOps, or similar test management tools.Experience performing structured manual testing.Strong understanding of software testing principles and Agile development practices.Experience using Git and modern development workflows.Strong cross-functional communication skills, with a track record of translating between engineering implementation detail and QA/testing needs — this role requires working closely enough with developers to influence how testability is built into the application itself, not just testing it after the fact.Comfort engaging in design discussions and backlog refinement/story-writing, not just testing finished work — able to spot and articulate quality or testability risks early enough to influence how a story or design is written.A proactive mindset focused on quality, with strong analytical, troubleshooting, and problem-solving skills.Excellent communication and stakeholder collaboration skills.

Desirable

Experience testing AR, VR, or mixed reality applications.Practical experience using AI tools to improve QA or engineering workflows — e.g. AI-assisted test generation, code review, or defect triage — or a track record of driving adoption of new tooling/process more broadly.Experience testing outside the game engine layer — API, backend, or data integrity testing against services such as a CMS.Experience with Azure DevOps, GitHub Actions, Jenkins, or similar CI/CD tools.Experience working within regulated environments, such as healthcare.The pay range for this role is:40,000 - 50,000 GBP per year(Remote (United Kingdom))