Founding Engineer, Frontend

About the company

Our client is an early-stage company in New York building a real-time sports trading platform — a market where people take positions on live sporting events as they unfold. It is the kind of product where the interface is the product: prices move continuously, positions change while you watch them, and the difference between a market people trust and one they abandon is largely a matter of how well the frontend holds up under real-time data. The team is small and still close to its first users, so engineering decisions are made quickly and their effects are visible almost immediately.

The role

This is a founding frontend seat, and the person who takes it owns how the product looks, feels and behaves for every customer. You would set the frontend architecture rather than inherit it, and build the consumer-facing surface of a live trading product: market views, charts, portfolios and the real-time state that sits underneath all of them. The client is explicit that this is a frontend-first role, not a generalist one — but on a team this size you would be expected to reach into full-stack or backend work when a problem needs it. It suits someone who wants substantially more ownership than a larger company can offer, and who treats an early-stage founding role as a deliberate career step rather than a detour.

What you'll do

• Own the frontend architecture of a consumer trading product from the ground up, rather than inheriting someone else's
• Build real-time interfaces — live markets, charts, portfolios and the complex application state that drives them
• Ship the consumer-facing surface that every customer touches, and stay close to how it performs in front of real users
• Make product judgement calls about how the software should work and feel, not only how it should look
• Pick up full-stack or backend work when the problem calls for it, while keeping frontend as your centre of gravity
• Work directly with the founding team, with decisions made and shipped in days rather than quarters

Nice to have

• Experience building a trading, brokerage, prediction-market, crypto, fintech or fantasy-sports product, or something similarly data-intensive
• Experience with real-time interfaces involving charts, market data, portfolios or complex application state
• Early-stage, founding or zero-to-one product experience
• A track record of unusually high ownership, ambition or fast career progression

Tech stack

React-centred frontend work, with real-time data handling and complex client-side state management around live market data, charts and portfolio views.

Compensation & logistics

• $175k–$225k base, plus meaningful founding equity
• Full-time and on-site in the Chelsea office in New York, four to five days a week, with flexible hours
• You need to already live in New York City or the surrounding area — this is not a relocation role
• 2 to 8 years of experience preferred; more experienced candidates are considered where the background is exceptionally relevant