Lead Design Engineer

Who you are

• 5+ years in front-end engineering, ideally React and TypeScript, with libraries such as shadcn/ui
• Experience building and maintaining a design system in production, not just consuming one
• Data-dense interfaces at scale — virtualised tables, charting, performance under real load
• Fluency with AI-assisted development, and the specification skill described above
• Willingness to work directly with users and own the experience, not the implementation alone
• Comfortable as an editor and enabler: reviewing others’ work, teaching, holding a line
• Genuine curiosity about finance. You need not arrive knowing what a capital call is

What the job involves

• AI has made producing screens easy. It has not made products coherent. We are looking for someone to own the experience of Sesame end to end — the client journey, the interaction logic, the look and feel, and the consistency of all of it — and to build it
• If you are an engineer who has always had a view on how the product should look and behave, this is a role where that judgement is part of the remit rather than a side interest
• We have posted this role under two titles — Design Engineer and Product Experience Designer — to reach both backgrounds. Same role, same team. Apply once, to whichever fits you better
• How much of this you lead outright will depend on your experience and on how it fits with the team already in place. There is room to take on more over time
• The front-end experience layer. You will build the interfaces that matter most, particularly the dense and difficult ones, and help set the patterns others follow
• The design system. Developed in code with the rest of the front-end team, with a leading voice in what belongs in the system
• Look, feel and consistency. The product should feel like one thing, and you will help define what that one thing is and uphold it in review and in tooling
• The client journey. You will be in front of investment professionals, family offices and their advisors, and trusted to act on what you hear
• Craft in dense financial interfaces. Tables legible at scale, numbers at the right precision,
• You can say what is wrong with a flow, not just implement it faster
• You think in objects, relationships and states before components
• You have taste in what matters here: hierarchy, typography, density, restraint
• You are comfortable doing the upstream thinking, including what should not exist at all
• No portfolio required. Shipped interfaces we can look at, and the decisions behind them, is what we want to see
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The application process

• Our interview process is likely to include a portfolio or work conversation, a short practical exercise based on a real Sesame flow, and a working session with a product manager and an engineer. We adapt the steps to the candidate and will always tell you what to expect in advance

Benefits

• Stock options, with extra incentives for high performers for London and Paris-based employees
• Work between home and our offices with our hybrid working model
• Private health care coverage provided by BUPA
• Access to company Uber and Uber Eats account when working outside of normal office hours