Principal Software Development Engineer in Test (SDET)

Location: UK - London

Department: Tech & Engineering

Principal Software Developer in Test (SDET)

Location: London (Hybrid) | Practice Area: Technology & Engineering | Type: Permanent

Drive test automation innovation and engineering excellence in financial technology

The Role

As a Principal SDET at Capco, you'll lead the strategy, architecture, and implementation of robust automation testing frameworks across financial services projects. You’ll work closely with cross-functional teams to deliver quality-first solutions using the latest tools and practices. You’ll also mentor engineers, foster best practices in test automation, and help shape our quality engineering capability.

What You’ll Do

• Architect reusable, scalable test strategies and frameworks across web and mobile platforms

• Design, build, and maintain test automation scripts for UI, APIs, and services

• Integrate testing tools into CI/CD pipelines and manage cloud-based testing solutions

• Lead test data management, performance/load testing, and accessibility verification

• Mentor junior engineers and influence organisation-wide testing strategy and tooling

What We’re Looking For

• Strong experience in UI and mobile test automation using Selenium, WebDriver, Cucumber, or Robot

• Proficient in API testing (REST/SOAP) and tools like Postman or JMeter

• Experience with cloud-based test platforms such as BrowserStack, Sauce Labs, or Appium

• Solid understanding of test lifecycle tools such as Jira, Jenkins, GitHub, SonarQube

• Strong knowledge of HTML, JavaScript, CSS, ReST, JSON, and accessibility standards

Bonus Points For

• Development background and coding experience in Java, Ruby, or Python

• Load and performance testing experience using JMeter, LoadRunner, or Performance Center

• Cloud platform exposure (AWS, Azure, OpenShift, PCF)

• Experience with DevOps practices, Agile methodologies, and AAA accessibility standards

• Experience migrating on-premise systems to cloud ecosystems

Why Join Capco

• Deliver high-impact technology solutions for Tier 1 financial institutions

• Work in a collaborative, flat, and entrepreneurial consulting culture

• Access continuous learning, training, and industry certifications

• Be part of a team shaping the future of digital financial services

• Help shape the future of digital transformation across FS & Energy.

Benefits 

We offer a competitive, people-first benefits package designed to support every aspect of your life:

• Core Benefits: Discretionary bonus, competitive pension, health insurance, life insurance and critical illness cover. 

• Mental Health: Easy access to CareFirst, Unmind, Aviva consultations, and in-house first aiders. 

• Family-Friendly: Maternity, adoption, shared parental leave, plus paid leave for sickness, pregnancy loss, fertility treatment, menopause, and bereavement. 

• Family Care: 8 complimentary backup care sessions for emergency childcare or elder care. 

• Holiday Flexibility: 5 weeks of annual leave with the option to buy or sell holiday days based on your needs. 

• Continuous Learning:  Your growth, your way - minimum 40 hours of training annually. Take your pick; workshops, certifications, e-learning. Also, Business Coach assigned from Day One: Get one-on-one guidance to fast-track your goals and accelerate your development. 

• Healthcare Access: Convenient online GP services. 
• Extra Perks: Gympass(Wellhub), travel insurance, Tastecard, season ticket loans, Cycle to Work, and dental insurance.

Inclusion at Capco

We’re committed to making our recruitment process accessible and straightforward for everyone. If you need any adjustments at any stage, just let us know – we’ll be happy to help. We value each person’s unique perspective and contribution. At Capco, we believe that being yourself is your greatest strength. Our #BeYourselfAtWork culture encourages individuality and collaboration – a mindset that shapes how we work with clients and each other every day.

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