Senior/Staff Frontend Engineer
Fonoa
Software Engineering
United Kingdom · London, UK
Location
London, United Kingdom; Zagreb, Croatia
Employment Type
Full time
Location Type
Hybrid
Department
Engineering
About Engineering at Fonoa
Engineering is central to how we build the business. We focus on solving real customer problems, not just shipping features. We work in small, high-trust teams, with full ownership across the lifecycle, from design to production and beyond.
We value:
Ownership – engineers own what they build end-to-end
Simplicity – we break down complex problems into clear solutions
Thinking Big - we innovate with modern technologies (LLMs, AI Agents, etc.) to solve meaningful problems
Quality – scalable, maintainable systems are non-negotiable
Speed & iteration – we ship fast, learn, and improve continuously
Collaboration – we win as a team, not as individuals
Position Overview
As Fonoa continues to evolve beyond APIs into a broader platform experience, we are looking for a Frontend Engineer to help redefine how our products are designed, built, and experienced across the company.
This role goes far beyond implementing interfaces. You will play a foundational role in shaping the future of the Fonoa platform — from customer-facing products and internal tooling to the overall design system, interaction patterns, and frontend architecture that ties everything together.
We are looking for someone who cares deeply about product experience, systems thinking, and frontend craftsmanship. Someone who can work closely with product, engineering, and design to build products that feel fast, intuitive, and thoughtfully designed, while also helping define how frontend engineering operates and scales at Fonoa.
As our platform evolves toward more intelligent, agent-driven workflows, the frontend becomes a critical part of the experience. We want to move beyond traditional dashboards and workflows toward interfaces that feel more dynamic, contextual, and assistant-like, helping customers navigate complex compliance and tax operations in a much more seamless way.
This is a highly collaborative, hands-on role for someone who thrives in ambiguity, enjoys shaping products from first principles, and wants to have a meaningful impact on both the user experience and the engineering culture around frontend development.
We are not looking for someone to simply “build screens.” We are looking for someone who can help define:
How products should feel
How frontend systems should scale
How users interact with increasingly intelligent workflows
And how design and engineering work together to create exceptional products
What You Will Be Doing
Redesign and evolve product experiences across customer-facing and internal platforms
Help define and scale our frontend architecture, patterns, and design systems
Build fast, reliable, and intuitive user experiences across web applications
Collaborate closely with product, design, and engineering to shape new workflows and features
Contribute to the visual identity and frontend standards of the platform
Help evolve Fonoa from an API-first company into a broader platform experience
Build interfaces that support intelligent, assistant-like, and agent-driven workflows
Continuously improve frontend quality, performance, maintainability, and developer experience
Mentor and influence frontend standards and practices across the engineering organisation
What We’re Looking For
Strong experience building high-quality frontend applications and product experiences
Deep understanding of frontend architecture, state management, performance, and scalability
Strong product and design instincts, with attention to detail and usability
Ability to collaborate closely with designers and product teams from concept to production
Experience designing and evolving frontend systems and reusable component libraries
Builder mentality with high ownership and strong product thinking
Comfortable operating in ambiguity and shaping problems, not just implementing requirements
Strong communication and collaboration skills in cross-functional environments
Curiosity around AI-driven interfaces and how intelligent workflows change product experiences
API Documentation
For engineers, API design and structure are an important part of evaluating a role. You can explore our API and how we build products here: https://docs.fonoa.com/
Tech Stack
We use these technologies today, but we don’t hire for specific tools. We care about engineers who can understand problems, make good technical decisions, and choose the right tools for the job.
Backend: Node.js, Go
Frontend: React, TypeScript
Infrastructure: GCP, k8s, Terraform, Postgres
Note:
If you don’t think you have the full experience we’re looking for, but you could be a fit and are willing to learn, do apply anyway! We are building a diverse and inclusive team.
As part of the recruitment process at Fonoa, we process your personal data in accordance with our Privacy Notice for Job Applicants. This notice explains how and why your data is collected and used, and how you can contact us if you have any concerns.