Smart Contract Engineer in London

We are looking for a highly skilled Smart Contract Engineer with deep expertise in both Solidity (EVM) and Rust to join our elite engineering team at MLabs. In this role, you will be subcontracted to work directly with one of our premier clients—leading innovators in the DeFi space—building next-generation financial infrastructure on Base, Arbitrum, and other EVM-compatible networks.

As a bridge between the smart contract layer and high-performance systems, you will architect, develop, and secure complex DeFi protocols. You aren’t just writing code; you are building the "money legos" of the future, ensuring they are gas-efficient, battle-tested, and capable of handling significant TVL (Total Value Locked).

• Architect & Develop: Design and implement robust, production-grade smart contracts in Solidity for deployment on L2s like Base and Arbitrum.
• Systems Engineering: Build high-performance backend services, tooling, or blockchain components using Rust to support on-chain logic.
• DeFi Logic: Develop complex on-chain financial logic including AMMs, lending/borrowing mechanics, staking protocols, or yield-generating products.
• Optimization: Perform deep-dive gas optimizations and performance tuning for both smart contracts and Rust-based infrastructure.
• Security & Risk: Apply rigorous security best practices to protect against common DeFi attack vectors (reentrancy, oracle manipulation, etc.) and participate in internal code reviews.
• Solidity Expertise: Proven experience writing, testing (Foundry/Hardhat), and deploying smart contracts in a production environment.
• EVM Mastery: A deep understanding of the Ethereum Virtual Machine, including gas optimization, memory layout, and L2-specific nuances.
• Rust Proficiency: Professional experience building backend services or blockchain-related tooling in Rust, with a comfort level working across the full systems stack.
• L2 Experience: Hands-on experience deploying and managing protocols on Arbitrum, Base, or similar Rollup solutions.

• DeFi Background: Previous experience working on Decentralized Finance protocols (e.g., DEXs, Lending, Restaking, or Tokenomics-heavy systems).
• Architecture Tradeoffs: A strong grasp of on-chain vs. off-chain architecture and the security considerations specific to financial protocols.
• Upgradeability: Familiarity with common proxy patterns and upgradeable contract design is a major plus.

We offer highly competitive rates; salary bands are flexible and scale directly with your seniority and depth of DeFi expertise.

Work on the bleeding edge of Web3 with some of the most respected names in the industry.

Enjoy the flexibility of working from anywhere in a team that values autonomy and output over hours at a desk.

Deepen your expertise in both the EVM and Rust ecosystems through complex, real-world engineering challenges.

As a member of MLabs, you’ll have access to a network of elite engineers and the opportunity to rotate into different high-profile client projects as you grow.

Due to the high volume of applications we anticipate, we regret that we are unable to provide individual feedback to all candidates. If you do not hear back from us within 4 weeks of your application, please assume that you have not been successful on this occasion. We genuinely appreciate your interest and wish you the best in your job search.

At MLabs, we are committed to offer equal opportunities to all candidates. We ensure no discrimination, accessible job adverts, and providing information in accessible formats. Our goal is to foster a diverse, inclusive workplace with equal opportunities for all. If you need any reasonable adjustments during any part of the hiring process or you would like to see the job-advert in an accessible format please let us know at the earliest opportunity.