Senior Smart Contract Engineer

Tangem is a high-tech company in the blockchain sector was founded in 2017, headquartered in Zug, Switzerland, with branches in North America, Eastern Europe, and APAC.

Tangem started with the idea of bringing digital assets to the masses using a unique combination of a smartcard-based hardware wallet and mobile applications. Company owns and promotes the technology of hardware cold-wallet for digital assets with secure and simple UX in 220 countries today. Our customers enjoy setup time within 1 minute with the ultimate security level for digital assets on their wallet. Tangem solutions offer multi-support of a growing number of thousands of tokens by a single wallet. SBI Crypto Investment Ltd., the digital asset venture investment company wholly owned by SBI Holdings Inc., has invested $15 million into Tangem in 2019 for mass adoption of blockchain technology.

About the Role

We’re looking for a seasoned Smart Contract Engineer to architect, build, test, and deploy robust on-chain protocols. You’ll develop core modules for asset handling, permissioned flows, trading, and collateralized lending-covering everything from secure vaults and multisig systems to automated swap and lending engines. Your work will power composable, trustless financial primitives.

Responsibilities

• Design and implement secure, gas-efficient smart contracts and upgradeable protocol modules;
• Build composable on-chain systems: multisig/permission modules, asset swaps, liquidity pools, collateral management flows;
• Develop and integrate automated off-chain agents (bots, oracles, monitoring tools) for system orchestration and maintenance;
• Write comprehensive unit, integration, and fuzz tests to ensure reliability and audit readiness;
• Ensure protocol security by following best practices, conducting threat modeling, and using static and formal analysis tools;
• Participate in peer reviews, architecture discussions, and cross-functional collaboration.

Requirements

• 4+ years of software engineering experience, with 2+ years focused on smart contract development (Solidity);
• Deep expertise in EVM and at least one non-EVM ecosystem;
• Proficient in development and testing frameworks (Hardhat, Foundry, Truffle, Brownie);
• Strong understanding of token standards (ERC-20, ERC-721, ERC-1155), cryptography, and DeFi mechanisms;
• Experience optimizing gas usage and implementing upgradeability and security patterns;
• Experience with secure multi-user transaction flows, such as multisig wallets, time locks, and role-based access.

Nice to Have

• Familiarity with formal verification tools (Slither, MythX, Echidna) and smart contract audits;
• Experience with Layer 2 solutions, bridges, and cross-chain infrastructure;
• Understanding of zero-knowledge systems and MEV considerations;
• Contributions to open-source DeFi or blockchain infrastructure projects.

What we offer:

• Stability, development, participation in the future unicorn's growth;
• Remote work from anywhere in the world, with a schedule aligned with GMT+3;
• Competitive salary in EURO/USDT;
• 20 working days of paid vacation;
• Birthday presents;
• Compensation for the purchase of necessary technical devices for the work;
• Paid sick leaves.