Senior Solidity Engineer — DeFi Smart Contracts

Placements24; Klerksdorp; On-site; ZAR 900,000 - 1,500,000; Full time

Benefits offered by this job

Health benefits

Career growth

Competitive salary

Job summary

Placements24 in South Africa seeks a Senior Smart Contract Developer in Klerksdorp to design, test, and deploy secure Solidity smart contracts for DeFi applications on Ethereum. You will work closely with product and engineering teams to deliver robust contracts and ensure high security standards.

As a senior member, you will mentor juniors, implement testing strategies with Hardhat/Truffle/Foundry, and stay updated on evolving DeFi protocols and EVM optimizations.

Qualifications

• Proven experience as a Smart Contract Developer
• Expert proficiency in Solidity
• Deep understanding of the Ethereum Virtual Machine (EVM)
• Experience with blockchain development frameworks like Hardhat, Truffle, or Foundry
• Knowledge of common smart contract patterns and security best practices (reentrancy, overflow/underflow)
• Familiarity with DeFi protocols and standards (ERC-20, ERC-721, etc.)
• Experience with version control systems like Git
• Strong analytical and problem‑solving skills
• Ability to work effectively in a team environment
• Bachelor’s degree in Computer Science or a related field, or equivalent practical experience

Responsibilities

• Develop, test, and deploy secure and gas‑efficient smart contracts using Solidity.
• Write comprehensive unit and integration tests for all smart contract code.
• Collaborate with frontend and backend developers to integrate smart contracts into dApps.
• Participate in the design and architecture of new blockchain features and protocols.
• Perform thorough code reviews to ensure quality, security, and adherence to best practices.
• Identify and mitigate potential vulnerabilities and risks in smart contracts.
• Optimize smart contract performance and upgradeability mechanisms.
• Stay up‑to‑date with the latest developments in Solidity, Ethereum, and the broader blockchain ecosystem.
• Troubleshoot and debug smart contract issues.
• Contribute to the technical documentation of smart contracts and related systems.

Skills

Solidity

EVM knowledge

Security best practices

DeFi knowledge

Smart contract testing

Team collaboration

Analytical thinking

Education

Bachelor's degree in Computer Science or related field

Tools

Hardhat

Truffle

Foundry

Git

Job description

Placements24 in South Africa seeks a Senior Smart Contract Developer in Klerksdorp to design, test, and deploy secure Solidity smart contracts for DeFi applications on Ethereum. You will work closely with product and engineering teams to deliver robust contracts and ensure high security standards.

As a senior member, you will mentor juniors, implement testing strategies with Hardhat/Truffle/Foundry, and stay updated on evolving DeFi protocols and EVM optimizations.