Senior Backend Engineer in City of London

For blockchain technology to revolutionise the digital economy, we require mass adoption, which can only happen with a drastic improvement in UX. Account abstraction is the path to achieving this, and a modular smart account infrastructure will provide the foundations to go beyond just UX improvements (e.g., gas fee and seed phrase abstraction) to a world where powerful on‑chain products become the norm. Build at the forefront of account abstraction infrastructure and prepare web3 for its first 1 billion users. At Rhinestone, our technology transforms smart accounts into an open platform for innovation.

Today, smart account development is cumbersome and complex. Only the core developers of the account contribute to its features, stifling creativity. Rhinestone enables any developer to build self‑contained components, called modules, that extend the functionality of smart accounts. Creating an “app store moment” and introducing a new primitive to supercharge on‑chain products. Some of the most compelling products are being built on smart accounts today, including WalletConnect’s Smart Sessions to revolutionise app UX, ZK Email to improve user privacy, Safe7579 to unleash the Safe app marketplace, chain abstraction solutions for instant cross‑chain transactions without bridging, and debit card offerings that can be plugged into any smart wallet.

The role involves developing the off‑chain infrastructure of Rhinestone’s Protocol. These core components will support the interoperability, security, and viability of an open and permissionless module ecosystem for smart accounts. The position will require experience with blockchain systems and building highly performant backend services. Rhinestone offers the opportunity to build at the frontier of one of the most important emerging technologies in the Ethereum ecosystem and collaborate with some of the most prominent thought leaders.

You’ll be expected to hold your own with leading teams across the space with whom we regularly interact, including Safe, core contributors of ERC‑4337, Biconomy, ZeroDev, Circle, and OKX, to name a few, to drive forward our development initiatives and ecosystem standards, like ERC‑7579. If you are nerd‑sniped by complex problems at the intersection of scalability, UX, and trustlessness, we’d love to speak with you! This is an opportunity for you to leave a mark on the broader ecosystem and become a true domain expert.

• Architect and design our off‑chain services using Rust to support feature growth and the rapidly changing requirements of being a startup.
• While your focus will be writing concurrent backend systems, you will also interact with our smart contract systems written in Solidity.
• Work closely with the team to ship new products and develop solutions for challenging technical problems.
• Deliver high‑quality code from concept until production.
• Dive into the code of other team members to provide thorough reviews and contributions outside of your own responsibilities.

• 3+ years of relevant experience with blockchain technology (EVM‑focused).
• 2+ years of experience writing Rust server code in a production environment (e.g., ethers.rs and/or alloy).
• Experience working with crypto wallets (preferably smart accounts), bridging technologies, blockchain nodes, relayer or intent‑based systems, and an understanding of Layer 2 solutions and their integration into the application layer.
• Ability to balance shipping quickly with building a stable infrastructure.
• Self‑starter, problem solver from the root cause, able to break down complex problems into simpler components and chart the phases of getting to a stable and scalable solution.
• A hustler mentality; founding a company, working in startups (pre‑series A), or building side projects (open source is a plus).
• Able to be a thought leader and highly collaborative to drive toward 10× outcomes.

• Onchain: Solidity (Foundry)
• Offchain backend: Rust, Node, Typescript, and various other JS/TS‑based frameworks
• Offchain frontend: NextJS, Typescript, and Tailwind

Location: London, UK or Remote (±2 hours of London timezone)

• Startup equity
• Opportunity to own complex part of tech stack end‑to‑end
• Flexible working hours and holidays
• Regular team meetups, offsites, and conferences
• A chance to work with the leading minds in account abstraction

Reach out to kurt@rhinestone.wtf to start the application process. Rhinestone employs a meritocratic mindset when hiring. Regardless of background, gender identity, age, religion, etc., we assess candidates by their ability to contribute, collaborate, and deliver excellent work.