Z-02_[業務委託/Contract] Solidity Engineer

‐ クロスチェーンブリッジ「TOKI」のスマートコントラクト設計・開発・保守（Ethereum、BNB Chain、Optimism、Unichain等に対応） ‐ セキュリティ・ガス効率・デプロイサイズを意識した設計およびコードレビュー ‐ プロダクトマネージャーと協業した要件定義・技術設計 ‐ 運用・ツール開発 ‐ 監視設計、トランザクション調査・デバッグなどの運用業務 ‐ 流動性管理など業務ツールの設計・開発 ‐ 外部監査会社との監査対応 Design & Development Design, development, and maintenance of smart contracts for the cross-chain bridge "TOKI" (supporting Ethereum, BNB Chain, Optimism, Unichain, and more) Design and code review with a focus on security, gas efficiency, and deployment size Requirements definition and technical design in collaboration with product managers Operations & Tooling Operational tasks including monitoring design and transaction investigation/debugging Design and development of operational tools such as liquidity management Coordination with external audit firms for security audits [About TOKI] TOKI is at the forefront of expanding IBC to non-Cosmos SDK blockchains. As key contributors to ibc-solidity, our current focus includes EVM blockchains such as Ethereum, BNB Chain (BSC), Avalanche, and Polygon. We're building an IBC bridge that connects EVM blockchains and Cosmos SDK blockchains. Our mainnet is now live, supporting Ethereum, BNB Chain, Optimism, and Unichain, with more chains coming soon. - https://twitter.com/tokifinance - https://toki.finance/

- Solidityでの商用または実ユーザー向けプロダクトの開発経験（DeFi、ブリッジ、DAO等の複雑なロジックを含むもの） - コントラクト設計・実装におけるセキュリティのベストプラクティスの理解 - 優れた論理思考力および問題解決能力 - アップグレーダブルなコントラクト設計（Proxy patterns等）の経験 - Foundry または Hardhat を用いたテスト設計・実装経験 ※当社ではFoundry（単体テスト）とHardhat（E2Eテスト）を併用。Fuzz testing、Invariant testingの経験があれば尚可 - ガス効率を意識した開発経験 - 他社プロトコルを含むスマートコントラクトのコードリーディング経験 - Experience developing commercial or user-facing products in Solidity (involving complex logic such as DeFi, bridges, DAOs, etc.) - Understanding of security best practices in smart contract design and implementation - Excellent logical thinking and problem-solving skills - Experience with upgradeable contract design (Proxy patterns, etc.) - Experience in test design and implementation using Foundry or Hardhat *We use Foundry for unit tests and Hardhat for E2E tests. Experience with fuzz testing or invariant testing is a plus. - Development experience with a focus on gas efficiency - Experience reading smart contract code, including third-party protocols

- Backend、ノードとのAPI連携やSDK開発などオフチェーンとの横断領域に関する専門性 - クロスチェーンプロトコル（IBC、ブリッジ等）の仕組みを調べたり、関連コードを読んだ経験 - DeFiプロトコル（AMM、Lending等）の設計・実装経験 - 監査会社または社内セキュリティレビュアーとしてのスマートコントラクト監査経験 - 静的型付言語(Golang, C++など)を用いた業務経験 - Expertise in cross-domain areas involving off-chain systems, such as backend/node API integration and SDK development - Experience researching cross-chain protocols (IBC, bridges, etc.) or reading related codebases - Experience designing and implementing DeFi protocols (AMM, Lending, etc.) - Smart contract audit experience at an audit firm or as an internal security reviewer - Professional experience with statically typed languages (Golang, C++, etc.)

- 複雑な問題を構造化し、主体的に解決策を導き出せる方 - セキュリティ意識が高く、リスクに対して慎重に対処できる方 - 新しい技術やプロトコルを自発的に探求し、チームに共有できる方 - 開発だけでなく、運用や保守まで責任を持って取り組める方 - 設計意図をドキュメントに落とし込み、他者と建設的な議論ができる方 - Able to break down complex problems and proactively derive solutions - Highly security-conscious with a careful approach to risk - Proactively explores new technologies and protocols, and shares findings with the team - Takes ownership not only of development but also operations and maintenance - Able to document design decisions clearly and engage in constructive discussions with teammates