Senior Full Stack Engineer

Company Description

About us

Every company in the world, needs to understand who they are doing business with.

We are re-imagining how humans find, read and distil knowledge from the internet – at unprecedented scale and accuracy, to answer critical questions about suppliers, donors, investors and third parties. We are addressing a sector-independent problem for a global market.

We are pioneers, working at the forefront of AI and applied research, to build a fully distributed, heterogeneous and scalable system, using the latest technologies.

We help the world ‘do better business, faster’. Our clients include the world’s leading companies, charities, universities, law firms and financial institutions. Using Xapien, in minutes, they can do work that previously took hours and days.

We have over 100 customers, in 3 continents, last year we doubled in size and this year we plan to triple. Our investors include tech founders, professional investors and recognised institutions, including Sequoia Capital.

If you are bright, driven and excellent at what you do, then we would love to explore you building your career with us. We're actively seeking exceptional individuals who are not only bright and driven but also excel in their field. If this describes you, we're eager to discuss the possibility of you joining our team and building your career with us.

Job Description

The Challenge

Our product is experiencing tremendous demand, presenting us with the exciting challenge of scaling our platform and technology. We need to deliver accurate insights while doubling down on how we architect, coordinate, and maintain our subsystems. We’re doing all of this against a backdrop of continuous innovation and refinement.

The Role

We are looking for a Fullstack Engineer (Go + React) to help scale and evolve the core Xapien platform as we grow rapidly.

Working directly with our Head of Engineering, you will play a key role in shaping the future of our product. This position involves a mix of backend and frontend development, systems design, and collaborative problem solving across the stack.

We are seeking someone with a strong background in modern web development and microservice architecture, and a mindset for clean, maintainable code.

Here’s what you will be responsible for

• Designing and building scalable microservices in Go, as part of a growing platform architecture.
• Developing intuitive and performant React components to enhance our frontend experience.
• Collaborating closely with product and design teams to turn complex user needs into elegant technical solutions.
• Writing clean, testable, and maintainable code across the stack.
• Participating in architectural discussions and helping shape engineering best practices.
• Troubleshooting and resolving production issues across services and systems.
• Contributing to CI/CD pipelines, observability, and automation alongside platform engineers.

Qualifications

Your Skills & Experience:

Must-haves to be successful in this role:

• Strong experience writing backend services in Go.
• Proficiency in React and modern JavaScript/TypeScript.
• Solid understanding of microservices architecture, RESTful APIs, and service-to-service communication.
• Experience working with cloud infrastructure (e.g. AWS, GCP or Azure).
• Strong grasp of software engineering fundamentals: testing, documentation, performance, reliability.
• Excellent communication and collaboration skills: you're comfortable working cross-functionally with engineers, designers, and product managers.
• A team-first mindset: open to feedback, different perspectives, and alternative approaches to coding and code styles.

Nobody can do everything, but here are a few related things we’re interested in:

• Experience working lower in the stack, e.g., databases, infrastructure, Kubernetes, or observability tooling.
• Exposure to CI/CD tooling
• Interest in natural language processing, AI, or distributed systems.

Additional Information

Here’s our promise to you:

• We are going to work with you - to build a rewarding and fulfilling career with the opportunities, challenges and resources you need to do you your best work.
• We succeed together- you will own a meaningful part of the business through our employee shares & equity programme.
• Private health insurance to keep you in tip-top condition.
• Life Insurance - let’s hope nobody ever needs this!.
• Unlimited holidays - yes, it’s really uncapped.
• A £1k wellness and development fund per year (including access to Wellhub - formerly Gympass).
• We equip each new team member a high-spec MacBook.
• Regular team lunches and gatherings.
• Fun and inclusive monthly social events, from go-karting to mini golf to karaoke to rounders in the park.
• Two days paid volunteering per year.
• X day – one whole company day off every year so we can all switch off Slack and reset.
• Flexible and hybrid working.