Haythem Sellami
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.
Projects & Contributions
- Babe CoProcessor - A Coprocessor built on top of SUAVE.
- WorldID Arbitrum State Bridge - A WorldID state bridge implementation Mainnet↔Arbitrum.
- Judge at HackMoney 2022.
- Speaker at ETHIndia 2021.
- Mindful Cash - Winner of ETHOnline 2021 hackathon.
- UpSideDai - Winner of ETHDenver 2020 hackathon.
- CherrySwap - Winner of ETHBerlinZWEI hackathon.
- Curvy MolochDAO - A fork of MolochDAO that implements a bonding curve token for the guild bank.