Principal Software Development Engineer in Test (SDET)

Capco; Greater London; Hybrid; GBP 70,000 - 90,000; Full time

Benefits offered by this job

Discretionary bonus

Competitive pension

Health insurance

Continuous learning opportunities

Gympass(Wellhub)

Travel insurance

Job summary

A leading financial technology firm in the UK seeks a Principal Software Developer in Test (SDET) to drive innovation in automation testing. This role involves leading the implementation of testing frameworks across financial projects, mentoring engineers, and collaborating with cross-functional teams. Candidates should have strong experience in UI and mobile automation testing, API testing, and using test lifecycle tools. The position offers a hybrid work model and a competitive benefits package tailored to support every aspect of life.

Qualifications

• Strong experience in UI and mobile test automation.
• Proficient in API testing and tools.
• Solid understanding of test lifecycle tools.

Responsibilities

• Architect reusable, scalable test strategies across platforms.
• Design, build, and maintain test automation scripts.
• Integrate testing tools into CI/CD pipelines.

Skills

UI and mobile test automation using Selenium, WebDriver, Cucumber, or Robot

API testing (REST/SOAP) with tools like Postman or JMeter

Test lifecycle tools such as Jira, Jenkins, GitHub, SonarQube

Tools

JMeter

LoadRunner

Performance Center

Job description

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

Bonus Points For

• Development background and coding experience in Java, Ruby, or Python
• Load and performance testing experience using JMeter, LoadRunner, or Performance Center
• 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.

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.
• 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.