Haythem Sellami
About
Passionate about Smart Contract Engineering, Rust and all things Open Source. 6+ years of experience designing and deploying production-grade DeFi protocols. Worked on lending, AMMs, derivatives, and yield allocation protocols. Deep understanding of Solidity, EVM, and protocol security best practices.
Experience
Senior Smart Contract Engineer
Euler Labs
Nov 2023 - Apr 2025
- Designed and implemented Euler Earn, a capital allocation protocol that allows vault managers to deploy funds into any ERC-4626–compatible vaults.
- Contributed to the test suite of Euler V2, a next-generation lending and borrowing protocol.
- Contributed to EulerSwap, a novel AMM leveraging Euler V2's lending positions for enhanced capital efficiency. Focused on the factory and periphery contracts, and handled integrations with DEX aggregators including 0x, ParaSwap, and Tycho Protocol.
- Conducted internal security audits and code reviews to ensure protocol robustness and maintain code quality.
Senior Smart Contract Engineer
Opyn
Apr 2020 - Nov 2023
- Wrote technical specifications and designed core components of options and derivatives protocols.
- Built multiple robust smart contract systems from the ground up, including Gamma Protocol (first on-chain options protocol) and Squeeth (first power perpetual token).
- Developed and deployed strategy vaults like Crab (delta-neutral on Squeeth) and ZenBull, integrated with Euler V1.
- Built and maintained bot infrastructure for liquidations, oracles, and monitoring using Node.js, Python, OpenZeppelin Defender, and Google Cloud.
- Integrated with AMMs, oracles, cross-chain messaging systems; deployed across multiple L2s.
Smart Contract Developer
Freelance
Jul 2018 - Mar 2020
- Built smart contracts for a pooled-liquidity money market and Oracle aggregation contracts for Alkemi Network.
- Worked with Coinsence, incubated by UNICEF Innovation Fund, to build a communities based fundraising system, built on top of Aragon framework.
- Contributed as part of The DAOincubator group on researching and implementing bonding curve systems.
- Designed bonding curve token mechanics and DAO contracts for Trojan DAO.
