Remote Senior Solidity Developer

Placements24; East London; Hybrid; ZAR 900,000 - 1,600,000; Full time

Benefits offered by this job

Health insurance

Retirement contributions

Job summary

Unknown is seeking a Senior Solidity Developer to design, implement, and optimize secure smart contracts for DeFi platforms. The role is remote-first with asynchronous collaboration across a global team, focusing on high-performance contracts for Ethereum-compatible networks.

You'll contribute to security audits, testing, gas optimization, and upgradeability patterns, working with Hardhat/Foundry, and aligning with rigorous DevSecOps practices. A strong background in blockchain tech is essential.

Qualifications

• 5+ years of software development with 3+ years in Solidity.
• Deep understanding of Solidity and the EVM.
• Experience with DeFi protocols and token standards is preferred.
• Experience with testing, security reviews, and audits.

Responsibilities

• Design, develop, test, and deploy secure smart contracts using Solidity.
• Perform code reviews and security audits to mitigate vulnerabilities.
• Develop and maintain test suites for robustness and reliability.
• Optimize gas usage and collaborate with frontend/backend teams.

Skills

Solidity

Ethereum

DeFi protocols

Security auditing

Education

Bachelor's or Master's in CS/SE

Tools

Hardhat

Truffle

Foundry

Job description

About the Role

Our client is a globally distributed leader in decentralized finance (DeFi) and Web3 infrastructure. We are actively recruiting a highly experienced Senior Solidity Developer to join our fully remote engineering team. This role is crucial for the design, development, and optimization of secure, high-performance smart contracts that form the backbone of our innovative financial products. You will collaborate with a talented international team of engineers, product managers, and researchers to push the boundaries of what's possible in decentralized finance. As a remote-first company, we value asynchronous communication, autonomy, and a results-oriented approach. You will have the opportunity to work on complex challenges, contribute to open-source projects, and make a significant impact on the future of finance. This position offers the ultimate flexibility, allowing you to work from anywhere while being an integral part of our mission. The role is fully remote, supporting our global team conceptually near East London, Eastern Cape, ZA , but operating worldwide.

Key Responsibilities

• Design, develop, test, and deploy secure and efficient smart contracts using Solidity.
• Write high-quality, maintainable, and well-documented smart contract code for various blockchain platforms (e.g., Ethereum, Polygon, Binance Smart Chain).
• Conduct thorough code reviews and security audits to identify and mitigate potential vulnerabilities.
• Develop and maintain comprehensive test suites for smart contracts, ensuring robustness and reliability.
• Optimize smart contract gas usage and execution performance.
• Collaborate with front-end and back-end engineers to integrate smart contracts into decentralized applications.
• Research and implement best practices for smart contract development, security, and upgradeability patterns.
• Stay current with the latest developments, emerging trends, and security considerations in the DeFi and blockchain space.
• Contribute to technical discussions, architectural decisions, and knowledge sharing within the engineering team.

Requirements

• Minimum of 5 years of professional software development experience, with at least 3 years focused specifically on Solidity smart contract development.
• Expert-level understanding of Solidity and the Ethereum Virtual Machine (EVM).
• Deep knowledge of DeFi protocols, token standards (ERC-20, ERC-721, etc.), and common smart contract design patterns.
• Proven experience with smart contract development frameworks (e.g., Hardhat, Truffle, Foundry) and testing methodologies.
• Strong understanding of blockchain fundamentals, cryptography, and security best practices.
• Experience with version control systems (Git) and CI/CD pipelines.
• Excellent analytical, problem-solving, and debugging skills.
• Strong communication skills, comfortable working asynchronously in a remote, distributed team.
• Bachelor's or Master's degree in Computer Science, Software Engineering, or a related field, or equivalent practical experience.

Benefits

• This is a fully remote position offering a highly competitive salary, performance bonuses, and comprehensive benefits including health insurance and retirement contributions.
• You will have the opportunity to work on groundbreaking DeFi projects, collaborate with industry leaders, and significantly influence the direction of decentralized finance.
• Our client provides a generous budget for home office setup, professional development, and attending relevant conferences.
• We foster a culture of innovation, collaboration, and work-life balance.
• Join our dynamic, remote-first team and help build the future of decentralized financial systems.