Senior Software Engineer

At Gamma, we’re more than just a leader in Unified Communications as a Service (UCaaS). We’re a fast-moving technology organisation delivering innovative voice, data, and mobile solutions across Europe.

Our product and service portfolio is at the heart of what we do — powering reliable, scalable communications for thousands of businesses. Behind the scenes, our engineering teams design, build, and maintain the software systems that generate real business impact.

We combine the agility of a start-up mindset with the stability of a leading European business. Collaboration, ownership, and continuous improvement define how we work — and we’re always looking for people who want to build meaningful technology at scale.

Senior Software Engineers are responsible for developing and maintaining the Group Products suite of proprietary telecommunication solutions. Building new features and functionality across the platform and web/desktop user interfaces. In this role you will be a member of the Product Engineering function at Gamma, responsible for building and maintaining high-quality software applications in an agile environment.

You will ensure that solutions meet requirements and adhere to engineering best practices. As a Senior Full Stack Software Engineer you will also play a key role in mentoring team members and fostering their professional growth.

• Collaborate with product and engineering peers to scope, plan and estimate requirements, ensuring all solutions are well thought through and future proof.
• Evaluate trade‑offs between technical solutions, providing recommendations that balance performance, maintainability, and delivery timelines to support leadership decision‑making.
• Develop new features and functionality across the platform and applications, whilst maintaining the stability of existing codebase, using Type Script, Node.js and React.
• Integrate with relevant third‑party services and tools where required, ensuring best practice integration rules are adhered to and integrations are stable.
• Develop APIs using best practice standards and conventions.
• Produce Solution Design documents for review before implementation including detail on security considerations, testing required and potential impacts across the stack.
• Take ownership of delivery timelines for assigned work, proactively identifying and communicating risks, blockers, and dependencies to appropriate stakeholders.
• Constructively challenge technical approaches and processes, proposing and driving improvements to team practices and ways of working.
• Use unit and E2E test frameworks to ensure a high level of coverage across the platform and web applications.
• Support, participate in, and actively encourage, Test‑Driven Development (TDD) practices and pair programming to maintain code quality and knowledge sharing.
• Support code deployment by maintaining CI/CD pipelines.

• Experience of front‑end and back‑end systems
• Strong experience with Type Script in production applications, with demonstrated ability to design scalable systems
• Proven experience mentoring engineers at various levels through code reviews, pair programming, TDD practices, and technical coaching
• Experience in evaluating and adopting new technologies and practices
• Experience with AWS (preferred), Azure or GCP
• Strong experience using unit & E2E test frameworks (e.g. Jest, Playwright)
• Experience maintaining CI/CD pipelines to build and deploy code, working to platform standards
• Kubernetes (Not required but beneficial)
• VoIP/WebRTC experience (Not required but highly beneficial)

At Gamma, we believe in work‑life balance, which is why we offer 25 days of annual leave, plus an extra day off for your birthday. We also provide a volunteer day, allowing you to support a cause that matters to you.

Family is important to us. With enhanced maternity and paternity pay, we support you at every stage of life. Our contributory pension scheme helps you plan for the future, with Gamma increasing contributions in line with yours.

Your wellbeing comes first. We offer group income protection, life assurance (four times your…