Senior SDET

Senior SDET

Are you looking to impact and be part of something special, such as shaping the future of healthcare? Do you take pride in building and maintaining robust test automation frameworks? Are you passionate about improving deployment processes for high-impact products?

Boxes ticked? If so, read on.

At Semble, we are on a mission to enable health professionals to amplify their impact. We improve the way healthcare is delivered to millions of people by providing doctors and their teams with powerful, innovative, intuitive, and secure software. Our cloud-based clinical system is already used by thousands of clinicians, making their lives easier and saving them money, while structuring their health data to help research.

We are a passionate and driven team, lucky to unite under strong cultural drivers:

• Impact - We do work that matters.
• Collaboration – We are in it together.
• Human touch – We care deeply.

This role can be fully remote in the UK and EU (with occasional travel to our London office) within +/- 2 hours of the GMT time zone. We are unfortunately not able to consider candidates located outside these locations and time zones at this stage.

What you will be doing  

The Senior SDET, Frameworks role will lead the evolution of Semble’s test automation capability and help make quality a shared engineering discipline. You will:

• Lead the transformation towards a Quality Agent System, using AI agents and deterministic automation to continuously identify coverage gaps, generate and maintain tests, detect flaky tests, support exploratory testing, and surface reproducible defects.
• Design safe, maintainable agent workflows with clear responsibilities, isolated execution, human review, and appropriate controls. Agents should assist engineers and SDETs, not replace human judgement or merge their own changes.
• Establish the foundations required for this system, including a stable Playwright framework, reliable CI integration, ephemeral test environments, test data management, quality observability, and structured test knowledge.
• Set up meaningful quality gates in CI and PR workflows, including coverage validation, framework conventions, high-risk code checks, and actionable failure reporting.
• Rationalise our overcrowded E2E suite by identifying tests that belong at unit, API, or integration level, keeping E2E focused on critical user journeys.
• Build and maintain a cross-layer coverage map and risk-based defect view, helping teams understand where quality gaps exist and where automation investment will have the greatest impact.
• Expand test coverage and surface quality gaps earlier in the development lifecycle, including through test scenario generation, mutation testing, and AI-assisted exploratory testing.
• Conduct proof-of-concepts for non-functional testing, including performance, accessibility, security, and reliability testing.
• Contribute to company-wide quality strategy, tooling decisions, quality metrics, and shift-left adoption alongside the wider SDET and Engineering teams.
• Coach engineers and SDETs on effective test design, the testing pyramid, Playwright, and contributing to the shared framework.

What we are looking for  

At a Senior level at Semble, we will expect you to be mostly autonomous in your scope and to own and solve complex tasks or lead projects independently. You will work with peers from different functions and have an impact across department. You may be in a mentoring role for more junior team members and should be able to influence effectively and lead by example throughout the company.

• 5+ years of professional experience as SDET or Test Automation Engineer
• A strong track record of designing, building, and evolving automation frameworks that are reliable, maintainable, and easy for engineers to adopt.
• Hands-on experience building AI-augmented or agentic quality workflows, not only using tools such as Cursor or Claude to generate test code.
• A pragmatic approach to AI adoption, with awareness of data privacy, security, clinical safety, cost, and false-positive risks.
• Strong commercial experience with TypeScript-based automation frameworks. Playwright experience is highly desirable.
• Experience with test coverage strategy and applying the testing pyramid to reduce unnecessary E2E testing.
• Experience with write unit, component, API and integration tests.
• Experience with performance testing tools, such as k6, is desirable.
• Knowledge of non-functional testing, including performance, accessibility, security, and reliability.
• Exposure to DevOps tools and cloud infrastructure, including Jenkins, Bitbucket, Datadog, and AWS.
• Strong written and verbal communication skills, with the confidence to represent the SDET function, challenge assumptions, and defend quality in release discussions.

What you’ll get in return  

• The great feeling coming with knowing you do something that matters: shaping the future of healthcare!
• £65-75k package (based on your experience and the value you can bring)
• Autonomy and ownership – we’ll set the vision and share the context, then we trust you to run with things – that’s the reason we hire you!
• 36 days off: 25 holidays +bank holidays +3 extra days (birthday and ‘feel good’ days) - that we will expect you to actually take so you can recharge and rest.
• Private Health Insurance – covering physical and mental health, as well as dental and optical!
• Get the tech you need - You will get the latest MacBook (unless you prefer Windows) and take your pick across a wide range of equipment to set up your home office ergonomically.
• Work alongside an inspiring team – our two founders have started Semble after a successful startup exit, and your future colleagues are all knowledgeable and innovators in their field.
• Fantastic office space in Central London, right outside Monument - with a roof terrace, weekly animations, loads of natural light, and cute doggies!
• The usual free bits coming with nice offices (barista coffee, tea, fruits, happy hours and activities.