Senior DeFi Engineer - Nexus Mutual

Nexus Mutual is building a decentralized alternative to traditional insurance, enabling individuals and institutions to protect themselves against risks across the crypto ecosystem.

We are looking for a Senior DeFi Engineer to help design and build the next generation of onchain risk and capital infrastructure at Nexus Mutual. You will work at the intersection of DeFi, smart contracts, financial engineering, and protocol design, building systems that manage real economic value and operate securely at scale.

This is a highly technical role for an engineer who is comfortable going beyond implementing specifications — someone who wants to understand the underlying financial mechanisms and contribute to how the protocol itself should work.

What You'll Do

• Design and implement smart contracts and DeFi protocols that underpin Nexus Mutual's risk, capital, staking, and coverage infrastructure.

• Develop and improve mechanisms for capital allocation, liquidity, staking, pricing, incentives, and risk management.

• Work closely with protocol, product, and research teams to translate complex financial mechanisms into robust onchain systems.

• Analyze existing DeFi protocols and primitives to identify opportunities for integration, optimization, or novel protocol design.

• Build integrations with DEXs, lending protocols, liquidity venues, oracles, and other onchain infrastructure.

• Develop mechanisms for deploying and managing capital efficiently across different risk and return profiles.

• Contribute to protocol architecture, economic design, and technical specifications — not simply implementation.

• Build highly secure, gas-efficient, and composable Solidity contracts.

• Develop comprehensive testing, simulations, monitoring, and tooling around protocol behavior.

• Participate in security reviews and help identify economic, smart-contract, and integration risks before deployment.

• Investigate protocol behavior using onchain data, simulations, and quantitative analysis.

• Work with engineers and researchers to evaluate potential protocol upgrades and new DeFi primitives.

• Contribute to the broader Nexus Mutual ecosystem through technical documentation, research, and open-source development.

• 5+ years of software engineering experience, with significant experience building production DeFi or blockchain systems.

• Strong expertise in Solidity and the EVM.

• Deep understanding of DeFi primitives, including areas such as:

  • AMMs and DEXs

  • Lending and borrowing

  • Staking and restaking

  • Liquidity provision

  • Yield strategies

  • Oracles

  • Token economics

  • Onchain governance

  • Capital allocation mechanisms

• Experience designing and deploying production smart contracts handling meaningful economic value.

• Strong understanding of smart-contract security, common attack vectors, and adversarial protocol behavior.

• Strong understanding of EVM execution, gas optimization, transaction mechanics, and protocol composability.

• Ability to reason about financial mechanisms and translate them into precise technical implementations.

• Experience with Foundry, Hardhat, or comparable smart-contract development tooling.

• Strong testing discipline, including unit, integration, fuzz, invariant, and/or fork testing.

• Comfortable working with onchain data and blockchain analytics.

• Strong software engineering fundamentals and ability to work independently on complex technical problems.

Particularly Valuable Experience

Experience in one or more of the following would be highly valuable:

• DeFi protocol design or mechanism design

• Insurance, risk markets, prediction markets, or financial derivatives

• Liquidity management and capital efficiency

• Automated market makers and pricing mechanisms

• Yield optimization or automated vault strategies

• Asset management protocols

• Risk modeling or quantitative finance

• MEV and transaction-ordering dynamics

• Cross-chain protocols and messaging

• Oracle design and manipulation resistance

• Protocol monitoring and risk infrastructure

• Building systems that manage $100M+ in TVL or transaction volume

• Contributions to major open-source DeFi protocols