Smart Contract Engineer

Ostium is on a simple mission: make it possible for anyone with a digital wallet to trade stocks, commodities, currencies, and crypto with full transparency. No brokers, no freezes, no hidden spreads. We’re replacing the opaque, offshore brokerage model with a transparent, permissionless trading stack built onchain. Every trade, deposit, and withdrawal is verifiable through open, auditable code. We’ve raised $27.9M+ from General Catalyst, Jump, LocalGlobe, Susquehanna (SIG), GSR, Alliance DAO, Soma Capital, Balaji Srinivasan, Meltem Demirors, and others.

Role (Remote / Full-Time)

We are seeking for a Smart Contract Engineer to lead the development of mission critical Solidity code powering our protocol. This role is ideal for someone with a deep understanding of the EVM, experience shipping production-grade contracts, and a passion for building next-gen DeFi infrastructure.

Responsibilities

• Design, implement, and audit Solidity smart contracts that enable perpetual trading on real-world assets
• Develop upgradeable and gas-optimized contracts for order execution, margining, funding rate settlement, and liquidation Integrate Chainlink’s Functions product and our proprietary oracle system with core protocol logic
• Collaborate closely with backend engineers to ensure seamless contract <-> off-chain service integration
• Build Foundry-based unit and integration tests, fuzzing scenarios, and formal assertions
• Participate in contract audits and bounty programs
• Write detailed documentation and participate in technical architecture reviews
• Stay on top of the latest DeFi protocol designs and security best practices

Requirements

• Strong proficiency in Solidity and deep understanding of EVM internals
• Experience with smart contract development tools: Foundry, Hardhat, Slither etc.
• Experience writing gas-optimized, upgradeable contracts (UUPS, Diamond Pattern, etc.)
• Familiarity with Chainlink, EIP-712, off-chain oracles, and cross-chain bridging
• Understanding of DeFi primitives: perpetuals, AMMs, LP vaults, oracles,
• collateralization
• Strong focus on test-driven development and coverage (Foundry preferred) Knowledge of on-chain security exploits and countermeasures
• Comfortable reviewing others’ code and being reviewed
• Experience with Subgraphs and The Graph protocol is a plus

Preferred Qualifications

• 2+ years experience building DeFi or Web3 protocols
• Contributions to open-source Solidity projects or DeFi protocols
• Previous experience building perpetual or derivatives systems
• Experience in TypeScript or Golang is a plus
• Experience working with fuzzing, formal verification, or audit tools
• Competitive programming or math olympiad background is a plus

Benefits

• Competitive compensation package
• Opportunity to work with cutting-edge blockchain technology
• Collaborative environment with highly skilled team members
• Flexible work arrangements
• Professional development opportunities

If you’re excited to define the next chapter in DeFi and believe in the future of on chain RWA trading, we’d love to hear from you.

Interested candidates should submit their resume, GitHub profile, and links to relevant contracts or audits you’ve worked on.