Job Description

Mass photometry — a technique developed at the University of Oxford for measuring the mass of individual particles in solution with a specialised microscope — is at the heart of what Refeyn does. Since spinning out in 2017, we've grown mass photometry from an academic breakthrough into a technology now widely used in biological research and increasingly adopted across the bioprocessing industry to develop and characterise drugs.

Join Refeyn's 10-person software team building the applications behind our mass photometry instruments — from instrument control and automation to data analysis, visualisation, and reporting. You'll work across the full development lifecycle, closely with product, UX/UI, and the wider R&D team.

Key responsibilities for this role include:

• Support the full software development lifecycle: planning, design, development, testing, deployment, and continuous improvement.
• Build and enhance:
• desktop and embedded user interfaces that are highly usable and tightly integrated with system and device logic
• automated instrument control, calibration routines, and failure-mode detection
• tools for analysing measurement data and interpreting results statistically
• Investigate, debug, and resolve complex software and system issues.
• Manage source code and branching strategy, and review teammates' pull requests.
• Collaborate across engineering and with stakeholders to translate technical and operational requirements into reliable, maintainable solutions.

We are ideally looking for someone with the following skills and experience:

• Python (OOP), plus Rust or C++, and modern development practices.
• GUI development experience (Qt, PySide6, QtQuick/QML) and a good eye for usability.
• Exposure to instrument or embedded systems — e.g. high-speed image acquisition; precision sample positioning (piezo/stepper stages); laser-scanning illumination control; automated sample handling (pipetting robots); failure-mode detection and recovery; data quality checks; near-real-time data processing.
• Familiarity with scientific computing and machine learning — NumPy, SciPy, Jupyter, PyTorch, Matplotlib.
• Knowledge of CI/CD (e.g. GitHub Actions) and version control with Git.
• Experience with Jira and Confluence in a hybrid agile/waterfall environment.
• Familiarity with testing and code-quality tools such as pytest, mypy, and pylint.

Don’t feel you have to tick all the boxes to apply. Our team thrives on shared learning and collective growth.

Why work for Refeyn?

Compensation and core benefits

• We anticipate a base salary of £40,000 to £60,000 for this role, depending on candidate experience
• Hybrid working - minimum 3 days in office
• 25 days annual leave per year in addition to bank holidays
• Up to 7% employer matched pension contribution
• Private health insurance plus critical illness cover, income protection and life insurance
• Give as You Earn and Cycle to Work salary sacrifice schemes.
• Annual Company and Individual bonus scheme
• Paid volunteer day

Family Friendly Benefits

Refeyn offers YellowNest Nursery Scheme to all employees once probation is passed, and new parents can benefit from up to 17 weeks fully paid maternity, adoption and shared parental leave, 4 weeks fully paid paternity leave, plus an annual allowance for emergency childcare.

Supporting your Development

All employees receive access to Linkedin Learning which offers thousands of courses to support their personal and professional development. We also run frequent training sessions on both hard and soft skills.

Values-Led

Refeyn is committed to celebrating each other’s differences and creating a dynamic, driven and diverse culture where everyone can flourish. We are proud to have been awarded Committed Status by the Inclusive Employers Standard in 2024 and are working hard to create a safe and empowering environment for all.

We firmly believe that there is great strength in building teams with different voices, experiences, perspectives, and backgrounds so that we can continue to share the team workload and enable our customers to succeed, and we welcome applicants from all sections of society to join us on our mission to advance discovery through innovation.

Expected interview plan

• First stage Teams interview (30 minutes)
• Take-home coding challenge
• Onsite panel interview and site tour (90 minutes)

Refeyn is proud to use anonymised hiring practices. Identifying information such as a candidate's name, email address, date of birth and photo will not be visible to the hiring manager when they review CVs.