Senior Smart Contract & Backend Developer (Solidity, TypeScript)

About the Role We are looking for a highly skilled Senior Smart Contract Developer with a strong background in Solidity, TypeScript, and backend engineering. The ideal candidate will be responsible for designing, building, auditing, and maintaining on-chain logic while also contributing to off-chain services, APIs, and database integrations. This position requires strong communication skills in English, attention to detail, and a passion for debugging and problem solving. Responsibilities • Architect, develop, and maintain smart contracts primarily using Solidity • Design and implement secure and gas-efficient on-chain logic aligned with business and protocol requirements • Integrate blockchain components with backend services written primarily in TypeScript • Build, document, and maintain REST and/or GraphQL APIs • Work with databases (SQL/NoSQL), modeling data and ensuring performance and reliability • Participate in technical planning, code reviews, audits, and security assessments • Own debugging and testing end-to-end — on-chain, off-chain, tooling and integrations • Collaborate closely with founders, engineers, auditors, and product stakeholders • Maintain accurate and clear English-based technical documentation and communication • Research and propose improvements, best practices, and new capabilities across the stack Requirements • 5+ years of professional software engineering experience • 3+ years of Solidity development experience • Strong knowledge of Ethereum ecosystem, ERC standards, wallets, gas optimization, and on-chain patterns • Proficiency with TypeScript, Node.js and modern backend architectures • Experience building and consuming APIs (REST, WebSockets, GraphQL) • Solid understanding of data modeling and databases (PostgreSQL, MySQL, MongoDB, Redis or similar) • Strong testing mindset (Hardhat, Foundry, Jest or similar) • Excellent debugging skills and passion for deep problem investigation • Fluent or near-native English communication skills, written and spoken • Ability to work independently with strong accountability and ownership • Familiarity with security considerations: reentrancy, flash loans, oracle risks, underflows/overflows, access control, upgradeability, etc. Nice to Have • Experience with auditing smart contracts • Familiarity with Layer 2 and cross-chain patterns • DevOps familiarity (Docker, CI/CD pipelines, infrastructure as code)  When applying, mention the word CANDYSHOP to show you read the job post completely. This is a beta feature to avoid spam applicants. Companies can search these words to find applicants that read this and see they are human RNzQuMjIwLjQ5LjI1MwM