Principal Test Automation Engineer

We are looking for a passionate Principal Test Automation Engineer to help us drive our organisations approach to automated testing across all development squads. This is a hands-on technical role where you will be building the framework yourself, in our codebase where you will work along side the squads who use it.

  You will be working within a cross functional team where you’ll build a containerised testing framework that creates isolated infrastructure for each test run. You’ll define CI/CD test strategies, introduce contract testing to reduce reliance on end-to-end tests, and establish enforceable standards that development squads can confidently adopt   Role: Principal Test Automation Engineer  Location: Liverpool City Centre HQ / Hybrid (3 days in office) Salary: £70,000 - £80,000 (dependent on experience) Working Hours: 37.5 hours per week, Monday to Friday   What you will be doing: 

Design and build the shared test harness. Ephemeral infrastructure per test run, test data seeding and teardown, third-party stubbing, database and message assertion probes. Ship it as a versioned package squads consume rather than fork   

Define how we classify tests by what they touch, and settle what belongs in CI and what belongs in CD  

Establish the patterns for component, contract, API, end-to-end, UI, regression and performance testing, each with a working reference implementation in our own codebase  

Own test data. Seeding through UI automation, API calls and direct database writes, with isolation that makes parallel execution safe   

Design the quality gates in our Azure DevOps pipelines, and own how fast and how reliably tests run, including the flaky test problem  

Work inside squads, pairing and reviewing, so teams get self-sufficient rather than dependent on you  

Be the escalation point when a squad is stuck on test engineering   

Lead root cause investigation into production incidents and test flakiness, and make sure what you find is covered by regression afterwards  

Keep the conventions and agent instruction files current so AI coding tools extend the framework consistently rather than inventing their own patterns  

Represent quality engineering in architecture and design forums, as a peer to Tech Leads and Principal Developers  

Own the automation metrics that matter, and use them to drive an improvement backlog rather than to report status 

Our Tech Stack:

Backend: xUnit, WebApplicationFactory, Testcontainers for .NET, WireMock.Net, MassTransit Test Harness, Respawn, Bogus, Verify  

Web and Mobile: Playwright with TypeScript, Maestro, Vitest, React Testing Library, Mock Service Worker  

Testing (cross-cutting): Postman, Pact for contract testing, axe-core for accessibility, k6 and NBomber for load and performance, SonarCloud quality gates  

Infrastructure: Azure, Docker, Kubernetes (AKS), Nginx, RabbitMQ, Azure Service Bus  

Tooling and Practices: Azure DevOps, Git, CI/CD pipelines, Agile methodologies 

    What we are looking for: 

Senior or Principal-level experience in test automation or quality engineering, where you built the framework rather than worked within one somebody else built  

Strong TypeScript and Playwright. Maestro or similar for mobile  

Working proficiency in C# and .NET. You'll be writing component and integration tests against our microservices with xUnit or NUnit, and seeding test data through domain code rather than raw SQL  

Docker and containerised test environments, including standing up infrastructure per test run with Testcontainers or equivalent  

Service virtualisation and HTTP stubbing, using WireMock or similar, to test a service in isolation  

Experience testing event-driven systems. Asynchronous messaging, eventual consistency, and asserting on published messages. We run RabbitMQ and Azure Service Bus through MassTransit  

Contract testing between services with Pact or equivalent, covering message schemas as well as HTTP  

Test data management across UI, API and database, with isolation that supports parallel runs, and synthetic or anonymised data throughout  

SQL Server, including database-level assertions and a realistic view of how schema change affects a test suite over time  

CI/CD pipeline and quality gate design, ideally in Azure DevOps  

Authentication in automated tests. Token acquisition, Entra ID, and sensible handling of test credentials  

A track record of bringing other engineers on through pairing and code review  

Able to influence technical direction across squads without having authority over them 

  Grow with Acorn  At Acorn Insurance, we’re proud of our Liverpool roots — and even prouder of how far we’ve come. As part of the Acorn Group, we bring over 40 years of specialist insurance expertise to the table. From humble beginnings, we’ve grown into a national leader, now employing 1,700+ people across the UK and reached a milestone £750 million in total value of insurance policies written in 2024.  We’re growing fast, with new opportunities emerging every week. That growth is largely due to the values we share: 

🦏 We run through walls for our customers and each other 

🐐 We challenge the status quo 

🐧 We succeed when we help those around us succeed 

🐆 We decide quickly when the smart thing to do is use our judgement 

Benefits: 

🌴 A maximum of 35 days’ holiday (depending on role and tenure) including bank holidays, with additional buy/sell options 

🧠 24/7 mental health support & free counselling available 

☝ Grow with us: Through career fairs, leadership programs, and learning on the go! 

💸 Flexible benefits, including early access to salary via our internal platform 

🏡 Hybrid working options to support work-life balance and individual needs 

🎉 Recognition awards, social events & more  

  Our Commitment to our colleague’s:   These aren’t just words — they’re the principles we live by. And we’re proud to back them up with real action, earning recognition and accreditation from leading organisations that share our commitment to people and growth: 

🧠 Mindful Employer – championing mental health and wellbeing 

♿ Disability Confident Level 1 & 2 – creating accessible, inclusive opportunities 

🌸 Menopause Friendly accredited – supporting every stage of life 

🎖️ Armed Forces Covenant signatory – honouring those who serve 

🎖️ Armed Forces Defence employer recognition scheme - Supporting those who serve 

🏆 Great Places to Work 2024/25 – fostering an engaging and positive workplace culture 

📈 Best Place to Work for Development – proud to be investing in people’s future 

👩‍💼 Best Place to Work for Women – breaking down barriers to women's career progression 

If you’re looking for a company with a strong culture, real career progression, and a people-first approach — all rooted in the heart of Liverpool — Grow with Acorn.  A Few Things to Know Before You Apply  We’re really excited that you’re considering joining Acorn! To help everything go smoothly, here are a couple of things to keep in mind:  If your application is successful, we will commence relevant employment checks prior to you commencing employment with us. These will include a standard criminal record check and an insolvency register check.    🌍 Visa Requirements Because our training is quite comprehensive, we can only consider applicants who have at least one year remaining on their Graduate or Post-Study Work visa. At the moment, we’re not able to offer visa sponsorship.  💬 We’re Here to Support You We’re committed to creating an inclusive, supportive workplace where everyone can flourish. If you need any adjustments during the recruitment process—or once you’re part of the team—just let us know. Whether it’s flexible hours, adapted equipment, or a bit of extra support, we’ll work with you to make sure you can do your best work.  #LI-JL1