Lead Software Engineer / Developer (Ruby TypeScript React

Are you a polyglot Software Engineer with Developer Experience, API / SDK development skills?

You could be joining a highly regarded provider of serverless real-time infrastructure for the Internet that processes billions of messages a day and powers everything from live chat and VoIP calls to real-time pricing and stock availability for a multitude of services around the globe.

As a Lead Software Engineer you'll own the technical strategy and architecture for one or more Developer Ecosystems (iOS, Web, Infra/Automation), define and drive best practices for API and SDK design, ensuring consistency, usability and scalability and lead complex, cross-team initiatives to expand and improve client libraries.

You'll oversee the full development lifecycle, from design through to release, maintenance and product evolution, mentoring more junior engineers and reviewing contributions, raising the technical bar across the team. You'll also guide and manage external contributors and open-source collaboration and act as a key interface with the developer community, incorporating feedback into product direction.

• You're a senior software engineer with experience of building developer tooling and APIs
• You have strong hands-on experience with Ruby, TypeScript and React
• You have experience within a product focussed B2B SaaS environment
• You have experience of making technical decisions that drive projects and raise the bar
• You're comfortable with AI tools such as Claude and Cursor and understand how they can be used to optimise processes
• You're customer and product focussed
• You're collaborative and pragmatic with experience of technically leading and mentoring others
• You have a thorough understanding of Computer Science fundamentals such as OOP, Data Structures, Design Patterns

As a Lead Software Engineer / Developer you will earn a competitive salary package including:

• Salary to £130k
• EMI share option scheme
• 28 days annual leave
• Enhanced maternity and parental leave packages
• Your choice of kit and home-station set up
• Personal learning and development budget (£1000 p/a + 5% time to work on your own projects)
• BUPA Health Insurance + dental costs + mental health and wellness
• Pension, Life Assurance, Income Protection
• Fully paid one month sabbatical at five years' service
• Gym subsidies, Cycle to work scheme and more

At Client Server we believe in a diverse workplace that allows people to play to their strengths and continually learn. We're an equal opportunities employer whose people come from all walks of life and will never discriminate based on race, colour, religion, sex, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status. The clients we work with share our values.