Principal Front End Developer in London

We are seeking an exceptional Principal Front End Developer to architect our front‑end ecosystem and guide our team into an AI‑native future. This role combines hands‑on development with strategic leadership, driving innovation in our user interfaces while mentoring a talented front‑end team in adopting AI‑native workflows. The ideal candidate will shape our front‑end architecture, liaise closely with the principal developer team (including backend and product) to ensure architectural alignment, and guide the company in elevating UI development standards.

As our Principal Front End Developer, you will champion agentic coding workflows, influence the product roadmap, and ensure our UI components—the primary interface for our clients—are built with scalability, security, and velocity at the forefront. Beyond writing code, you’ll act as a bridge between engineering and product, using data, user feedback, and industry best practices to refine and optimize our web applications. Aside from our API, these UI components are the main interaction our clients and their customers have with Yapily, making your role critical to our success.

The ideal candidate should have expert level skills in front‑end development, as well as strong proficiency in back‑end development and APIs. Excellent development experience with modern JavaScript frameworks, back‑end technologies and testing tools are necessary. Our technical stack includes React, Playwright, Vite, Node.js, Java, Spring. Experience in aggregation businesses or open banking is also highly advantageous.

• Lead and mentor the Front End team, driving a culture of technical excellence and the adoption of AI‑native development workflows.
• Architect and oversee the front‑end ecosystem, guiding the company‑wide strategy for UI development, accessibility, and scalability.
• Liaise closely with the developer team (including backend and product) to ensure architectural alignment and seamless integration across platforms.
• Architect and implement complex, high‑performance SPAs while championing agentic coding workflows to improve developer velocity.
• Define technical standards, establish robust code review processes, and ensure security and performance optimization across all interfaces.
• Partner with Product Management to define the technical roadmap, ensuring UI components align with broader business and product goals.
• Lead cross‑functional initiatives, fostering collaboration between design, backend, and product teams to deliver cohesive, high‑quality customer‑facing features.
• Ensure application security through implementation of best practices and regular audits.
• Take ownership of quality assurance processes, including testing strategies and automation.

This list is not exhaustive, and there may be other tasks that we ask you to be involved in from time to time. Above all, you are flexible and want to add value wherever you can. You understand that in a small and relatively young organisation, priorities change. Not only will you expect to be asked to input and lead in other areas, but you’ll be instigating this yourself.

For your new role:

• You love innovation – it’s wired into your DNA.
• You’re commercially minded.
• You think outside of the box and are pragmatic. You will bring in and iterate on the experience, skills and knowledge of best practice that you have seen elsewhere. You are always looking for better and cost effective ways to do things.
• You have aligned experience. You have worked in a fast past financial services environment before. You have designed, operationalised and right sized processes to ensure effective engineering management.
• You are driven and curious. You ask questions and you strive to understand.
• You understand that your stakeholders will have different strengths. You’re happy to learn from them and to share your expertise.
• You enjoy solving problems. You don’t get flustered easily. You’re comfortable managing your time and can be counted on to skilfully handle issues.
• You understand the importance of attention to detail and ensuring quality outputs. Everything you produce is of high quality.
• You have exceptionally high integrity. You’ll treat all interactions with the confidentiality, sensitivity and diplomacy they deserve.
• You have a can‑do approach. You think on your feet. Switching up tasks and juggling multiple priorities comes naturally to you.

25 days holiday a year (plus bank holidays) in the UK, other applicants subject to country guidelines. We also offer an additional one days holiday after 1 years service up to the value of 5 days over 5 years. We’re serious about work/life balance and operate hybrid working, giving you the flexibility to work from home, working from our amazing office space or work abroad for up to 30 days per year – Nomad Working. We offer enhanced Paternity and Maternity leave. Comprehensive Private Medical Insurance through BUPA. Comprehensive and tailored mental health support through an award winning provider. Company Pension Scheme. £200 annual Learning and Personal Development budget. £200 work from home set up allowance, which you can put towards your home office. Cycle To Work Scheme. Employee Referral Scheme which offers £1000 per employee referral. Team Activities – we have a monthly social budget to support getting together over pizza. Daily snacks provided in the office. Dog Friendly Office.