[Hiring] Senior Software Development Engineer in Test @Collinson Group

Role Description

Key Responsibilities — Senior SDET

• Take ownership of test automation frameworks, building them from the ground up where needed and improving existing ones.
• Be the go-to person for framework design and good standards testing practices.
• Help shape the test strategy across products and services, making clear, practical decisions about coverage, risk, and release readiness.
• Write reliable, maintainable integration and end-to-end tests to the same engineering standards as production code.
• Build reusable utilities, mocks, and simulators that make testing easier for the wider team.
• Embed automated testing into CI/CD pipelines, giving engineers fast, meaningful feedback and confidence in their changes.
• Keep test suites and regression packs healthy by tackling flaky tests, removing duplication, and ensuring coverage stays relevant as products evolve.
• Test across front-end applications, back-end services, APIs, and distributed microservices, using tools such as Playwright, Cypress, REST Assured, and Postman where appropriate.
• Plan and carry out performance and load testing using tools such as k6, Grafana k6 Cloud, or JMeter, working with engineers to investigate bottlenecks and validate improvements.
• Use AI tools such as Claude, GitHub Copilot, or similar to support test design, scaffold and maintain frameworks, generate test cases, and investigate failures.
• Apply engineering judgement to review and validate AI-generated code and test results.
• Explore practical uses of AI agents for exploratory testing, fuzz testing, and anomaly detection, alongside hands-on investigation and risk-based testing.
• Where products include AI-powered features, develop evaluation approaches covering prompt regression, output quality and safety, and variability in model responses.
• Work closely with engineers, product managers, and delivery leads to build quality into requirements and design decisions from the outset.
• Coordinate across squads to test shared journeys, service contracts, and integrations.
• Stay hands-on throughout delivery: investigate defects and production issues, carry out targeted manual testing, validate fixes, and add automated coverage to prevent repeat failures.
• Bring an independent quality perspective to architecture and release decisions.
• Ask difficult questions, challenge assumptions, and raise concerns when the evidence does not support a release.
• Mentor engineers and other testers, share knowledge, and help create an environment where people can question decisions, surface risks, and learn from failures without blame.

Qualifications

• Evidence of testing craft through frameworks you have built, improvements you have delivered, open-source contributions, or examples you can discuss.
• Practical experience using AI coding assistants or agents, including writing effective prompts and critically evaluating their output.
• Experience with cloud-native testing, AWS environments, infrastructure as code such as AWS CDK, and consumer-driven contract testing with Pact.
• Experience evaluating AI-powered features and building repeatable checks for model behaviour.