Build the Future of Workplace Collaboration at Thomas
At Thomas, we’re redefining how teams connect and collaborate. Our AI-driven platform, Thomas Connect, delivers deep behavioural insights that help teams work smarter, not harder.
We're looking for a Senior Software Engineer to help us build scalable, high-performance applications that transform the modern workplace. If you're excited about solving complex problems, working with cutting-edge tech, and driving innovation in a fast-paced SaaS environment, read on.
Is This Role Right for You?
We’re not just building software, we’re revolutionising how teams collaborate. As a Senior Software Engineer, you'll play a key role in shaping our AI-powered platform, Thomas Connect, helping to build modern, scalable web experiences that drive real business impact.
We’re looking for someone who is analytical, innovative, and collaborative, with a passion for high-quality software, strong engineering principles, and methodical problem-solving. If you enjoy the balance between engineering excellence and elegant design, this is the role for you.
What You’ll Do
- Develop & scale modern web applications using C#, .NET Core, CosmosDB, Redis
- Design, build, and refine RESTful APIs to enable seamless data integration
- Create engaging, high-performance frontend experiences using React, JavaScript, HTML, and CSS
- Influence system architecture, contributing to design discussions and proposing innovative solutions
- Lead and participate in code reviews, promoting best practices and high engineering standards
- Collaborate with UX Designers, Product Managers, and Engineers to deliver impactful new features
- Optimize automated testing using tools like Jest, Playwright, and Vitest
- Mentor and support junior engineers, fostering a culture of learning and collaboration
- Continuously improve software quality, security, and performance
What We’re Looking For
🎯 Must-Have Experience:
✔ Strong C# skills with .NET Core and cloud-based backend technologies (CosmosDB, Redis)
✔ Expertise in JavaScript, React, and modern frontend technologies
✔ Experience building RESTful APIs and responsive, mobile-first web applications
✔ Deep understanding of asynchronous JavaScript and core browser concepts
✔ Experience with test automation tools (Jest, Playwright, Vitest)
✔ Agile mindset – comfortable working in fast-paced, iterative development cycles
💡 Nice-to-Have Skills (Bonus!):
➕ Experience working with Docker, Kubernetes, Microsoft Azure, or AWS
➕ Familiarity with microservices architecture
Thomas Assess – Our Talent Assessment Tool
We take hiring seriously—so seriously that we use our own AI-powered assessment tool, Thomas Assess, to ensure the best fit for every role. Our talent insights platform helps us hire without bias, focusing on the behaviours and skills that matter most.
Curious how it ? You'll get firsthand experience using Thomas Assess as part of the hiring process.
📢 Join us and help shape the future of workplace collaboration. Apply now to be part of our journey! 🚀
- Holiday – 25 days per annum, plus the opportunity to purchase up to an extra 5 days per annum through the salary sacrifice holiday buy scheme (plus an extra day off for moving house!)
- Early Finish Friday - Finish at 15:00 all year round.
- Hybrid Working - primarily working from home with some days as agreed with the People Manager from the office.
- An extra day off for your birthday and for moving house!
- Employment Assistance Programme - Access to Workplace Options which provides a complete support network that offers expert advice and compassionate guidance and is accessible 24 hours a day, 7 days a week, 365 days a year.
- UK Healthcare – cash plan where members of Team Thomas can claim back for various healthcare appointments (including dental and optical).
- My Specialist GP – a private GP surgery located in Marlow, which is available for all members of Team Thomas to use for emergency on the day appointments, paid for by Thomas.
- Gym Membership – Thomas will either pay up to £28 per month towards gym membership at any nationwide gym, or £28 per month towards membership at The Marlow Club (a gym and swimming pool located close to the Marlow office).
- Perkbox – a communication, health & wellbeing, and discount portal, allowing members of Team Thomas to keep up to date with business news, access information on health & wellbeing offerings and access discounts on a wide range of retail products and leisure activities.
- Personalised Feedback Session - with an enablement specialist to gain insight into own Thomas insights.
- Dress down policy – other than for client facing meetings where appropriate.
- Enhanced Maternity and Paternity Scheme.
- A Salary Sacrifice Pension Scheme.
Location: This role is based in the UK and aligned with our Marlow office
