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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Software Development Engineer in Test (SDET) - **Company:** LEGO Digital Play - **Location:** London, UK - **Salary:** £61,795.0 - **Contract:** Permanent contract - **Skills:** Clean Code Principles, Java (Programming Language), Application Programming Interfaces (APIs), Artificial Intelligence, Automation of Tests, C Sharp (Programming Language), Code Coverage, Continuous Delivery, Continuous Integration, Software Debugging, Video Game Development, Game Engine, Python (Programming Language), Software Reliability Testing, Software Engineering, Software Testing Automation Framework, Systems Integration, TypeScript, Production Code, SDET - **Published:** August 18, 2026 - **Apply:** https://www.adzuna.co.uk/jobs/details/5846388153 ## About the Role * Strong hands-on software engineering experience; you write clean, maintainable code and treat test automation as software engineering * Proven experience designing and building test automation frameworks from the ground up, not only writing tests within an existing one * Proficiency in modern testing approaches: the test pyramid, shift-left testing, contract testing, and risk-based test design * Hands-on experience building and maintaining CI/CD pipelines and integrating automated testing into them * Demonstrated experience using AI tools in a testing or engineering workflow, with sound judgement about their strengths and limits * Strong debugging and troubleshooting skills across platforms, versions and configurations, with a track record of driving down flaky tests * Fluency in one or more languages commonly used for test automation, such as C#, Python, TypeScript or Java * Excellent communication; able to work directly with engineers, explain quality trade-offs clearly and stay credible with the teams you support * Sound judgement and comfort with ambiguity; able to define a testing strategy where none yet exists * Awareness of safety, privacy, IP and compliance obligations and how they translate into test coverage Preferred Qualifications * Experience testing SDKs, developer libraries or platform APIs consumed by other engineers * Experience with game development or game engines such as Unity, including automated testing in a live project * Performance, load and reliability testing experience at scale * Experience with security testing or building security checks into a pipeline * Experience evaluating and selecting testing tools or vendors * Experience supporting a platform with meaningful compliance requirements, particularly those involving children's data * Early-stage or founding experience establishing quality practices for a new platform ## Description We are looking for a Software Development Engineer in Test to build test automation frameworks for our SDK's. This is a newly created role reporting to the Lead Engineer, Development Platform based in our London HQ., * Design, build and maintain test automation frameworks and harnesses for the platform's SDKs, APIs, libraries and services, treating test code with the same rigour as production code * Develop and run tests across the pyramid: unit, integration, contract, end-to-end and performance; ensure coverage is meaningful and repeatable * Build and own the continuous integration and continuous delivery test pipelines; make quality gates fast, deterministic and reliable so teams can ship with confidence * Apply AI-assisted testing tools to generate, maintain and triage tests, and set clear guidance on where AI accelerates the work and where human review is required * Diagnose failures to root cause across engine versions, platforms and configurations; drive down instability and keep the suite trusted * Establish reliability and observability for the test estate: clear reporting, actionable signals and metrics on quality, coverage and pipeline health * Partner with SDK and platform engineers to make testing a first class principle ("shift left testing"), embed testability into designs and feed defects back as clear, prioritised input * Uphold the platform's safety, brand integrity, privacy and IP obligations in test design, including validation of compliance-sensitive behaviour ## Related Videos - [Building a fully automated escape room](https://www.wearedevelopers.com/videos/735-building-a-fully-automated-escape-room) - [Do TypeScript without TypeScript](https://www.wearedevelopers.com/videos/327-do-typescript-without-typescript) - [Building Developer Experience - Brick by Brick](https://www.wearedevelopers.com/videos/1461-building-developer-experience-brick-by-brick) - [Coding an Immersive Copilot using Unity / .NET and Azure OpenAI!](https://www.wearedevelopers.com/videos/1204-coding-an-immersive-copilot-using-unity-net-and-azure-openai) - [Vuejs and TypeScript- Working Together like Peanut Butter and Jelly](https://www.wearedevelopers.com/videos/127-vuejs-and-typescript-working-together-like-peanut-butter-and-jelly) - [Testing .NET applications a Tool box for every developer](https://www.wearedevelopers.com/videos/704-testing-net-applications-a-tool-box-for-every-developer) ## Related Articles - [The 8 Best Code Testing Tools](https://www.wearedevelopers.com/magazine/402-the-8-best-code-testing-tools) - [What is Software Engineering?](https://www.wearedevelopers.com/magazine/289-what-is-software-engineering) - [Should senior developers refuse interview coding challenges?](https://www.wearedevelopers.com/magazine/29-should-senior-developers-refuse-interview-coding-challenges) - [Dev Digest 120 - Apple and peers](https://www.wearedevelopers.com/magazine/455-dev-digest-120-apple-and-peers) - [Is Software Engineering Hard?](https://www.wearedevelopers.com/magazine/448-is-software-engineering-hard) - [The 12 Best Jobs for Software Engineers](https://www.wearedevelopers.com/magazine/401-the-12-best-jobs-for-software-engineers)