Principal Software Development Engineer in Test

Salary: £65,000 - 105,000 per year

Requirements:

• Strong experience delivering UI and mobile test automation using Selenium, WebDriver, Cucumber, Robot Framework, or similar technologies.
• Proven expertise in API testing (REST/SOAP) using tools such as Postman, JMeter, or equivalent testing frameworks.
• Experience working with cloud-based testing platforms including BrowserStack, Sauce Labs, Appium, or comparable services.
• Solid understanding of quality engineering tooling including Jira, Jenkins, GitHub, SonarQube, and modern CI/CD practices.
• Experience using AI-enabled tools responsibly to improve engineering productivity while maintaining appropriate human oversight, governance, accessibility, and software quality.
• Development experience using Java, Ruby, Python, or similar programming languages.
• Experience delivering performance and load testing using JMeter, LoadRunner, Performance Center, or equivalent tools.
• Exposure to cloud platforms such as AWS, Azure, OpenShift, or Tanzu/Cloud Foundry.
• Experience applying DevOps practices, Agile methodologies, and accessibility standards including WCAG/AAA.
• Interest in responsible AI, automation, and emerging quality engineering technologies to continually improve software testing and delivery.

Responsibilities:

• Lead the strategy, architecture, and implementation of robust test automation frameworks across financial services projects.
• Work closely with cross-functional teams to deliver quality-first engineering solutions using modern testing tools and practices.
• Mentor engineers, foster best practices in quality engineering, and help shape our automation testing capability.
• Champion AI-enabled ways of working and encourage the responsible use of approved AI and automation tools to improve engineering productivity, accelerate test delivery, and enhance software quality.
• Architect reusable, scalable test automation strategies and frameworks across web, mobile, and API platforms, applying AI-enabled engineering approaches where appropriate to improve efficiency and test coverage.
• Design, build, and maintain automated test suites for user interfaces, APIs, and backend services using modern testing frameworks.
• Integrate automated testing into CI/CD pipelines while optimising cloud-based testing platforms to support reliable and scalable software delivery.
• Lead test data management, performance and load testing, accessibility validation, and continuous quality improvement across delivery teams.
• Establish testing standards and encourage the responsible use of approved AI tools and automation to improve collaboration, productivity, and engineering quality.

Technologies:

• AI
• API
• Appium
• AWS
• Architect
• Azure
• Backend
• BrowserStack
• CI/CD
• Cloud
• Cloud Foundry
• Cucumber
• DevOps
• GitHub
• Support
• JIRA
• Java
• Jenkins
• JMeter
• Mobile
• OpenShift
• Postman
• Python
• REST
• Robot Framework
• Ruby
• SOAP
• Selenium
• Web
• UX UI Design

More:

We are Capco, a consulting firm in Londons Technology & Engineering practice area, hiring for a permanent Principal Software Developer in Test (SDET) role. We deliver high-impact technology solutions for Tier 1 financial institutions and help shape the future of digital transformation across Financial Services and Energy. You will work in a collaborative, flat, entrepreneurial culture with access to continuous learning, training, and industry certifications. We offer a people-first benefits package that includes discretionary bonus, competitive pension, health insurance, life insurance, critical illness cover, mental health support, family-friendly leave, backup care sessions, five weeks of annual leave with holiday buy/sell options, at least 40 hours of annual training, business coaching from day one, online GP services, and extra perks such as Wellhub, travel insurance, Tastecard, season ticket loans, Cycle to Work, and dental insurance. We are committed to an inclusive, accessible recruitment process and a culture where individuality and collaboration are valued.

last updated 34 week of 2026