Senior Software Development Engineer in Test

Senior Software Development Engineer in Test

Full-Time 63000 - 77000 £ / year (est.) Home office (partial)
Biller Genie

At a Glance

  • Tasks: Design and implement scalable test automation frameworks for rapid feedback and continuous testing.
  • Company: Join Biller Genie, a fast-growing B2B SaaS platform with ambitious plans in Belfast.
  • Benefits: Enjoy private health insurance, generous holiday, and a matched pension scheme.
  • Other info: Collaborative culture with opportunities for professional growth and development.
  • Why this job: Shape the future of quality engineering in a dynamic fintech environment using AI tools.
  • Qualifications: 5+ years in software testing, strong programming skills, and experience with test automation.

The predicted salary is between 63000 - 77000 £ per year.

Location: Belfast, Northern Ireland

Work Arrangement: Hybrid

Position Overview

We are seeking an experienced Senior Software Development Engineer in Test (SDET) to act as a catalyst for quality across our engineering organisation. You will be a first‑class engineer who builds & maintains our automated testing infrastructure, enabling rapid feedback cycles and the delivery of high‑quality software at speed. This is a technical leadership role: you will advocate for quality throughout the software development lifecycle, design test strategies, influence our test architecture, mentor others in test automation, and partner with engineering teams to build quality in from the ground up rather than test it at the end. We are an AI‑enabled engineering team, and we believe the future is about empowering engineers with the latest tools, building through custom skills, agents, and harnesses, and we are looking for people who embrace AI, are excited about the future, and want to shape the way we embed AI tooling throughout our developer experience. If you are passionate about quality engineering, comfortable using AI tooling to work faster and smarter, and want to shape testing practice in a fast‑paced fintech environment, we want you on our team.

About Us

Recently ranked #482 on the Inc. 5000 fastest growing companies in the United States, Biller Genie is an award‑winning B2B SaaS platform that is entering the Belfast market with ambitious plans to scale our team rapidly, with over 100 hires planned through 2028.

Primary Job Responsibilities

  • Test Architecture: Design and implement scalable test automation frameworks that enable rapid feedback and continuous testing
  • Quality Engineering: Partner with development teams to build quality into the development process through test automation, code reviews, and best practices
  • Innovation: Research and implement new testing tools and methodologies, including AI and agentic engineering approaches, to improve our testing efficiency and coverage
  • Continuous Improvement: Lead initiatives to enhance our testing infrastructure, practices and metrics to drive quality improvements
  • Technical Leadership: Mentor team members in test automation best practices and quality engineering principles
  • Perform other duties required by Management

Essential Criteria

  • BSc or MSc in Computer Science, Software Engineering or related field OR equivalent commercial experience
  • Minimum 5 years of software testing experience in SaaS environments
  • Strong proficiency in at least one object‑oriented programming language, ideally C#, though strong OO fundamentals in Java, Python or a similar language are equally welcome
  • Extensive hands‑on experience with test automation frameworks and tools (e.g. NUnit, xUnit, Moq, SpecFlow/Reqnroll, or the equivalents in your language of choice)
  • Experience with API testing tools and techniques (e.g. Postman, RestSharp)
  • Experience with UI/browser automation (e.g. Playwright, Selenium)
  • Practical experience working with AI and agentic engineering processes
  • Working knowledge of SQL and database testing
  • Familiarity with CI/CD pipelines and tools
  • Experience of cloud technologies such as Azure, AWS, GCP
  • Proficient with Git and related workflows
  • Strong attention to detail and work ethic
  • Strong analytical and problem-solving skills
  • Excellent communication (both written and verbal) and interpersonal skills
  • Ability to work effectively with cross‑functional teams
  • Legal right to work in the UK

Desirable Criteria

  • Proficient with Claude or Claude Code
  • Experience with performance testing frameworks and tools (e.g. k6, JMeter, NBomber)
  • Knowledge of security testing principles and tools
  • Experience with test data generation and management
  • Experience of LEAN software development practices
  • Experience with Azure Functions and Queues
  • ISTQB Advanced Level or relevant technical certifications
  • Experience in the Financial services industry
  • Experience mentoring engineers or leading a test/QA function

What We Offer

  • Private health insurance
  • Group life death benefit
  • Auto‑enrollment pension with employer contributions matched to 5%
  • 25 days holiday per year
  • 10 statutory/bank holidays per year
  • Opportunities for professional growth and development
  • A collaborative and innovative work environment

Our Mission

To provide an automated A/R platform that seamlessly integrates existing business processes for the SMB market.

Our Core Values

  • Get Shit Done Right: We work hard and ensure tasks are completed correctly and on time, every time.
  • Own it: We are subject matter experts who know what we know, and we are confident enough to speak up when we see something wrong.
  • Catch Up: We are high performers and love a fast‑paced environment.
  • Believe in the Genie: We are passionate about where we are going as a team, and we show we care.
  • Class Shines: We are articulate professionals who carry ourselves well and speak with purpose.

Please note we are unable to offer visa sponsorship.

Senior Software Development Engineer in Test employer: Biller Genie

Biller Genie is an exceptional employer, offering a dynamic and innovative work environment in Belfast, where experienced Full Stack .NET Engineers can thrive. With a strong focus on professional growth, employees benefit from private health insurance, generous holiday allowances, and a collaborative culture that embraces AI-driven development. Join us to make a meaningful impact in the fintech space while being part of a rapidly growing team that values expertise and creativity.

Biller Genie

Contact Details:

Biller Genie Recruitment Team

We think you need these skills to ace Senior Software Development Engineer in Test

Test Automation Frameworks
C#
Java
Python
NUnit
xUnit
Moq