Web3 React Senior Jobs in London, United Kingdom

About Plasma

Plasma is building the primary account for global money.

Money used to belong to a country. Increasingly, it belongs to a person or business moving through many countries. People and businesses now earn, spend, save, hire and invest across borders. Traditional banks cannot serve this new world.

Our first product, Plasma One, is a global money account: a place to receive, hold, send funds in seconds, earn yield and spend with a card in the local economy.

Underneath is the Plasma network, built from first principles for stablecoin payments. Stablecoins make dollars faster, cheaper and more reliable to move.

Technological revolutions obey power laws. The opportunity is to become where all global money lands first: where income arrives, balances grow, payments move, businesses operate, and new financial products are built.

The Team & Our Story

We are a global team of founders, operators and engineers, obsessed with building the best products. We work at the cutting edge of financial innovation, using stablecoins to create tools for consumers and businesses.

We operate with trust, clarity, and ambition: own your craft, move with urgency, contribute beyond your lane, back your teammates, debate rigorously, and keep raising the bar for what great means.

Depending on where your strengths and our needs align best, you'll join one of these teams:

• Consumer owns the core Plasma One product experience - onboarding, activation, retention, rewards, tiers, trading, earn, and account management. The team is responsible for growing funded users, engagement, balances, spend, and long-term retention.

• Payments owns the financial infrastructure that powers Plasma - accounts, ledgers, funding, payouts, card issuing, reconciliation, payment orchestration, and currency/rail integrations. The team is responsible for the reliability, scalability, and economics of moving and storing money.

• Business owns the Plasma experience for companies - the operating account for businesses that work globally: onboarding, receiving, holding, and sending money across borders, corporate cards and spend management, and the roles and approvals that keep teams in control of company money. The team is responsible for taking the product from its first business customers to general availability, and for growing the businesses that run on Plasma.

The Role

Plasma's product is where all of this becomes real to people: the app they open every day, the balances they watch grow, the card they spend with. We're looking for a mid-level to senior, fullstack engineer to join one of Plasma's engineering teams and own the product and client-side surfaces that team is responsible for. Our stack is TypeScript across the board - Node.js on the backend and React + React Native for the frontend

You'll report into your team's eng lead and partner closely with your product lead to ship production-quality experiences from the API down to the pixel.

The Work

• Build and own your team's product and client-side surfaces end to end, in React and React Native - from the API down to the pixel.

• Care as much about how a screen feels as whether it's correct: performance, responsiveness, and the small interactions that make the product feel trustworthy with someone's money.

• Design and build the systems: state management, data schema design and robust handling of real financial data

• Partner closely with product and design at the concept level, so the experience and the implementation move as one thing, not two departments.

• Own reliability: graceful handling of failures, retries, and edge cases in a product where mistakes cost people real money.

• Raise the bar on engineering quality within your team: architecture, testing strategy, performance budgets, and code review.

• Mentor other engineers and drive technical clarity on the product side of your team.

• You have very high agency and don’t wait to be told a problem to work on and proactively find new problems to solve

The Bar

• A mid-level to senior, hands-on engineer with a track record of shipping and owning production, fullstack systems end-to-end.

• Strong product sense: you notice when something feels slow, confusing, or untrustworthy, and you fix it without being asked.

• Comfortable taking product surfaces from zero to one, and then scaling them without losing clarity or performance.

• Strong judgment on tradeoffs: speed vs. polish, abstraction vs. control, simplicity vs. flexibility.

• You communicate clearly, write clean code, and can lead through technical and product decisions.

• Experience building product-facing or client-side systems at scale

• You make decisions based on data and use data to ground whether solutions work

Nice to have

• Experience with React Native or native mobile development.

• An eye for interaction and motion design, and a track record of partnering closely with product designers rather than just implementing their files.

• Fintech, banking, or crypto-native background.

• You’ve been a founder or early employee at a fast-paced, high agency startup

What's in it for you

• Above-market salary for the level of the role, with token compensation.

• A beautiful London HQ with gym access and daily food, for those who thrive in an office environment. Visa sponsorship and relocation support if you're joining from abroad.

• Premium health insurance for you and your family, fully covered by Plasma.

• Monthly wellness budget, whether that's the gym, therapy, sauna, or massage.

• All the tools and tech you need to operate at your best.

• Real ownership and responsibility from day one, with your work shipping to hundreds of thousands of people, moving millions of dollars every day.

Data Protection & PrivacyWe are committed to protecting the privacy and security of your personal data. Any personal information you provide during the recruitment process will be processed in accordance with the General Data Protection Regulation (GDPR) and applicable local data protection laws.