Principal Test Automation Engineer

Acorn Group; Liverpool; Hybrid; GBP 70,000 - 80,000; Full time

Benefits offered by this job

Hybrid working options

Mental health support

Career development

Flexible benefits

Recognition awards

Job summary

Acorn Group, based in Liverpool, is seeking a Principal Test Automation Engineer to lead the design and delivery of a containerised, shared testing framework. You will set CI/CD test strategies, introduce contract testing, and drive standardisation across squads in a hands-on role.

The position requires strong TS/Playwright skills, C#/.NET proficiency, and experience with Docker-based environments. Hybrid work enabled in Liverpool City Centre HQ.

Qualifications

• Senior or Principal-level role in test automation or quality engineering, leading framework development.
• Strong TypeScript and Playwright skills; mobile tooling is a plus.
• Proficiency in C# and .NET, writing component and integration tests against microservices.
• Experience with Docker-based test environments and per-test isolated infrastructure.
• Experience with service virtualization and HTTP stubbing (WireMock or similar).
• Contract testing (Pact) across services and message schemas.
• Test data management across UI, API and DB with parallel runs.

Responsibilities

• Design and build a shared test harness and ephemeral per-test infrastructure.
• Define what tests belong in CI vs CD and establish quality gates.
• Establish patterns for component, contract, API, UI, regression and performance testing with reference implementations.
• Own test data seeding and isolation to enable parallel test execution.
• Design quality gates in Azure DevOps pipelines and improve test reliability.
• Collaborate across squads, pair programming, and provide guidance to reduce bottlenecks.
• Lead root cause analysis of production incidents and flaky tests.
• Maintain framework conventions and AI tooling alignment with patterns.

Skills

Playwright

TypeScript

C# / .NET

Test automation

Docker

Testcontainers

Azure DevOps

Pact

WireMock

MassTransit

Pair programming

Code review

Tools

Testcontainers for .NET

WireMock.Net

Maestro

Kubernetes

Azure Service Bus

Job description

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 optionsto support work‑life balance and individual needs
• Recognition awards, social events & more

Our Commitment to our colleague’s:

• Mindful Employer – championing mental health and wellbeing
• Disability Confident Level 1 & 2 – creating accessible, inclusive opportunities
• Menopause Friendly accredited – supporting every stage of life