Sergiu
From Romania (UTC+3)
Sergiu – Solidity, JavaScript, Typescript
Sergiu is a senior Solidity and EVM smart contract engineer with strong experience in protocol architecture, multi-ledger rollups, and DeFi/NFT projects. He demonstrates ownership of complex blockchain solutions and solid judgment in security-sensitive environments. Sergiu mentors engineers through local hackathons and delivers Web3 training courses and presentations.
5 years of commercial experience in
Main technologies
Additional skills
Direct hire
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Let’s get started today!Experience Highlights
Lead Smart Contract Developer
It's a multi-ledger rollup built on the OP Stack, designed to enable enterprises and developers to use a single execution layer when interacting with assets and messages from different blockchains.
- Led core smart contract development for a multi-ledger OP Stack rollup connecting one L2 to multiple L1s.
- Adapted bridge and token flow logic for the multi-L1 architecture with robust security controls.
- Implemented token whitelisting, deposit/withdrawal flows, and upgrade mechanisms with comprehensive testing.
- Added fuzz testing support to improve coverage and catch cross-chain edge cases early.
Web3 Developer
It's a tokenomics-focused Web3 project that burns XEN to mint a new capped token, DXN. It's designed for users in the XEN ecosystem and aimed to combine deflationary mechanics, game theory, and multi-chain deployment.
- Contributed to smart contract development, tokenomics implementation, and front-end blockchain integration for DBXen.
- Built and tested core protocol logic while supporting multi-chain EVM deployments.
- Connected on-chain mechanics to the user-facing application for seamless functionality.
Web3 Developer
It's a Web3 DeFi/NFT product built on the XEN ecosystem that allows XENFT holders to mint a dual-balance NFT that combines NFT ownership with on-chain asset tracking and native-yield mechanics.
- Contributed to smart contract development and front-end blockchain integration for DBXeNFT.
- Implemented core NFT and protocol logic with secure wallet and on-chain interactions.
- Delivered user flows for minting, balance tracking, and rewards in the Web3 front end.
Web3 Developer
It's a decentralized, end-to-end encrypted messaging protocol built for users who want private communication without relying on centralized email providers.
- Developed smart contracts and a front-end for receiving/displaying blockchain messages.
- Integrated Moralis and implemented blockchain event decoding for accurate message data processing.
- Delivered end-to-end protocol logic, UI blockchain integration, and core user messaging flows.
Education
Computer Science
Master’s degreeLanguages
English
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