Senior Software Engineer, Frontend in London

Walr is the service-first data collection company built for the fast and the ambitious. Founded in 2020, we exist to elevate the role of the market researcher – not by adding more tools to juggle, but by removing the operational heavy lifting so teams can focus on what truly matters: insight, impact, and confidence. What sets Walr apart is relentless speed, obsessive service, and dedicated experts who show up every day for our clients and each other.

We’re a high-growth scale-up with 170+ employees across 9 countries, having doubled our headcount in 2025. At Walr, we’re redefining data collection through unmatched speed, obsessive service, and human expertise that others simply can’t match. Technology powers our momentum, but people make the difference. Here, you’ll be trusted to take ownership, encouraged to think boldly, and backed by a team that moves fast—together. If you want impact, growth, and the chance to build something that truly matters, Walr is the place to be.

As a Senior Software Engineer, Frontend, you’ll design, develop, and lead the delivery of complex user-facing applications across the Walr Platform. You’ll set technical standards for frontend engineering, mentor peers, and ensure our interfaces are accessible, performant, and a pleasure to use. This role is about leadership in execution, ownership of outcomes, and shaping your product’s future.

• Technical Excellence
  • Lead the design and delivery of complex frontend applications with TypeScript, ReactJS, and modern CSS, setting and upholding standards that promote maintainable, scalable code.
  • Build high-performance, responsive, and accessible (WCAG) user interfaces that function seamlessly across browsers and devices.
  • Drive architectural discussions on component design, state management, and frontend infrastructure, balancing technical excellence with business priorities.
  • Champion and evolve Walr’s component library and design system, ensuring consistency and reusability across product areas.
• Execution & Ownership
  • Take ownership of frontend system health, proactively identifying and resolving performance bottlenecks, build tooling issues, and technical debt.
  • Oversee the maintenance and evolution of frontend build systems, including bundling, transpiling, linting, and testing toolchains.
• Collaboration
  • Collaborate across teams – product, design, backend, QA, and customer success – to deliver solutions that delight clients and drive business value.
  • Mentor and coach engineers, multiplying team capability and contributing to a high-performance engineering culture through code reviews, pairing, and knowledge sharing.

• 5+ years of experience designing and delivering complex frontend web applications.
• Expertise in TypeScript, ReactJS and Redux, with a strong focus on component-based architecture and state management.
• Strong understanding of modern CSS, responsive design, and accessibility standards (WCAG).
• Experience building and maintaining component libraries or design systems.
• Proficiency with frontend testing frameworks (Jest, React Testing Library, Playwright).
• Solid understanding of REST APIs and backend integration patterns.
• Experience leading technical discussions, setting direction, and influencing architectural decisions.
• Strong product mindset, connecting technical work to customer and business value.
• Skilled in DevSecOps practices including CI/CD, automation, and security.
• Excellent communication skills, particularly in translating design requirements into technical solutions and communicating effectively with both technical and non-technical audiences.

• Experience with data visualisation libraries (D3.js, Chart.js, Recharts).
• Background in UX/UI design principles and working closely with designers.
• Experience in styled components using Shadcn and Tailwind.
• Familiarity with C# and .NET, supporting smooth integration across the stack.
• Experience with cloud platforms, especially Microsoft Azure, for frontend hosting and deployment.
• Experience with AI-assisted development practices, prompt engineering for code generation, or integrating AI tools into the development workflow.

• We Delight through Dedication: We go the extra mile, stay focused, and fix what’s not working. Fast.
• We Lead with Trust: We trust each other’s judgment and act with integrity. Always as partners.
• We Revel in Innovation: We challenge the status quo and try new ways forward. Progress over perfection.
• We Celebrate as a Team: We share wins, support each other, and believe we’re better as a collective.
• We Are Empowered to Act Like Owners: We take responsibility, make bold calls, and think big-picture.

We’re building a workplace that works for everyone. We know that teams thrive when they bring together different voices, backgrounds, and perspectives — so we’re actively working to make sure everyone feels seen, heard, and valued. Whether it’s how we hire, grow talent, or shape our culture, inclusion is at the heart of what we do. If you’re passionate, curious, and ready to make an impact, you belong here.