Senior Software Developer in Test (SDET)

Position: Senior Software Developer in Test (SDET)

Reports to: QA Lead

Location: We are a remote first organization, +/- 2 hours from UK 

Salary: £60,000 - £70,000

About MillTech

MillTech provides advanced FX and cash management solutions to increase market access, reduce costs and automate manual workflows.

With a focus on automation, integration and connectivity, we have pioneered an independent risk management and liquidity solution for fund managers, institutions and global corporates, which is purpose-built to deliver best execution at scale.

Our end-to-end operational workflow enables automation, standardisation and cost transparency on all FX transactions and cash movements.

A highly secure platform centralises all client FX and cash activities to enhance oversight whilst increasing control, all at no additional costs. It offers quick onboarding routes, multi-bank best execution and hedging management services.

Headquartered in London, the world’s largest FX hub, MillTech provides services to clients in the United Kingdom, United States, Canada, Switzerland, Belgium, Denmark, Ireland, Luxembourg, Norway and Liechtenstein. MillTech is authorised and regulated by the UK’s Financial Conduct Authority (FCA FRN 911636) and registered with the USA’s National Futures Association (NFA). 

Your mission

We move large sums of money around, and quality is key to everything we do. As our most senior hands-on test engineer, you will be embedded in a full-stack product team and own the technical quality engineering discipline end-to-end. Where the QA Lead sets the quality vision and develops the team, you make that vision executable — turning strategy into working, scalable automation and raising the technical bar through your craft.

Your responsibilities in this role will include:

• Own the design, implementation, and evolution of scalable test automation frameworks
• Define and execute technical test strategies from the earliest stages of feature design
• Drive automated test coverage across the product estate, including CI/CD pipeline integration and regression pack health
• Act as the technical authority on testing within the product team — tooling decisions, code quality standards, and hard engineering problems
• Partner with the QA Lead to translate quality strategy into engineering execution
• Triage and resolve defects efficiently, with a focus on systemic fixes
• Own QA engineering metrics and use data to drive continuous improvement
• Evaluate and recommend new tools, libraries, and testing approaches
• Provide technical mentorship and code review to less experienced test engineers

Required skills:

• Experience working with Foreign Exchange or Cash Management systems
• Deep knowledge of QA methodologies across the full testing spectrum — unit, integration, API, E2E, regression
• Playwright at scale, including framework design and CI/CD integration
• JavaScript and TypeScript — clean, maintainable, reviewable test code
• Strong SQL for validating complex data flows and financial transactions
• Proven track record designing or significantly evolving test automation frameworks
• Excellent written and spoken English; able to communicate technical risk to non-technical stakeholders
• Keen eye for detail, personal integrity, and commitment to excellence
• Confident use of AI tools to accelerate test authoring, coverage analysis, and documentation

Additional skills you may have:

• AWS and/or Azure experience, particularly around test environment provisioning or cloud-based test execution
• Experience with performance, load, or security testing in a financial services context
• Familiarity with FX pricing, payments, or trade lifecycle systems

What we offer in return:

Our commitment is to help you flourish in this role, through support with your professional development, opportunities to be involved in key projects, and exposure to challenges that you may not be offered in a larger organisation.  We will provide:

• A competitive salary with annual reviews;
• 25 days’ paid annual leave plus an additional day per year of service;
• Excellent staff development and training opportunities;
• Flexible working arrangements including remote working;
• Medical insurance;
• Dental insurance;
• EV Scheme and Cycle to work scheme;
• Enhanced maternity and paternity leave;
• 1 day off for charity work per quarter and many other benefits!

How to apply?

At MillTech we believe that diversity and inclusion are essential for fostering innovation and building a strong, supportive work environment. We are committed to embedding the best equality and diversity practices into all our activities, making us an inclusive, welcoming, and exciting place to work. We would welcome candidates from all backgrounds and experiences.

We would love to hear from you if you think that you’re a good fit for this role.  To apply you should upload your CV.  One of the team will then be in touch with you to discuss the next steps.