Senior Backend Engineer

The role

We're looking for a Senior Backend Engineer to join our growing Product Engineering team. As a Backend Engineer, you'll play a pivotal role in helping to build the canonical tools and products to protect digital assets and preserve self-sovereignty in a post-quantum world.

This role is a full-time, fully remote position in Europe (GMT to GMT+2).

What you'll be responsible for

• Own and evolve a security-critical core library used by multiple applications and runtimes

• Design, implement, and maintain execution logic for blockchain transactions, signing flows, and protocol interactions

• Build and maintain robust abstractions over blockchain RPCs, transaction construction, and network interactions

• Enforce strict security boundaries around key handling, signing, and cryptographic operations

• Define and uphold API stability guarantees, versioning strategy, and backward-compatibility policies

• Contribute to internal security standards, documentation, and engineering best practices

What you bring

• Strong proficiency in Rust & Typescript (ideally both)

• Experience building performant backend services, APIs and libraries at production scale

• Practical experience in Web3 development e.g. Ethereum JSON-RPC, Viem/Ethers, Contract ABIs, call encoding/decoding etc

• Good knowledge of CI/CD, service deployments, containerisation

• Strong security knowledge e.g. authentication/authorization, signature verification, secrets management, encryption (especially post-quantum)

• High competency with automated testing e.g. unit, integration and e2e testing

• Strong English communication

What we'd love to see

• Understanding of ERC-4337 smart wallet patterns e.g. EOA vs AA concepts, multisig basics, validation flows, bundlers/paymasters

• Experience with frontend development in React (or similar)

• Experience with iOS development or mobile development using React-Native

• Experience developing and maintaining protocols

• Experience with decentralised identity, DIDComm, encrypted messaging protocols

• Open-source contributions to Web3, Account Abstraction, Decentralised identity, Cryptography

Equal Opportunity

We are committed to equal employment opportunity and believe that diverse teams build better products. All qualified applicants will receive consideration without regard to any protected characteristic under applicable law.