Senior Backend Engineer (Cryptography, Blockchain)

TL;DR

Senior Backend Engineer (Cryptography, Blockchain): Building and maintaining security-critical backend systems that power next-generation digital asset infrastructure with an accent on API design, blockchain transaction logic, and cryptographic operations. Focus on enforcing strict security boundaries, defining API stability standards, and contributing to internal security best practices.

Location: fully remote role based in Europe (GMT–GMT+2)

Salary: $122,000

Company

An applied research and engineering lab operating at the intersection of cryptography, blockchain, and emerging technologies, focused on securing digital assets.

What you will do

• Own and evolve a security-critical core library used across multiple products.
• Design and maintain execution logic for blockchain transactions and signing flows.
• Build robust abstractions over blockchain RPCs and network interactions.
• Enforce strict security boundaries around key management and cryptographic operations.
• Define API stability, versioning, and backward compatibility standards.
• Contribute to internal security standards, documentation, and best practices.

Requirements

• Strong proficiency in Rust and/or TypeScript.
• Experience building high-performance backend services, APIs, or libraries.
• Hands-on Web3 experience (Ethereum JSON-RPC, ABIs, transaction encoding).
• Solid understanding of CI/CD, deployments, and containerisation.
• Strong security fundamentals (auth, signing, secrets, encryption).
• High competency in automated testing and clear English communication.

Nice to have

• Familiarity with ERC-4337 and account abstraction concepts.
• Frontend experience (React or similar).
• Mobile development experience (iOS or React Native).
• Protocol or decentralised identity experience.
• Open-source contributions in Web3 or cryptography.

Culture & Benefits

• Fully remote work.
• Opportunity to work with an applied research and engineering lab focused on cutting-edge technologies.
• Be part of a growing Product Engineering team.