Common Blockchain Coding Challenges in Smart Contract Developer Interviews

If you're preparing for smart contract developer interviews, it’s important to practice common blockchain coding challenges that test your Solidity skills and smart contract logic. Typical Blockchain Coding Challenges: Write a Basic ERC20 or ERC721 Token Interviewers often ask candidates to build a simple token using OpenZeppelin. It checks your understanding of token standards, minting, burning, and access control. Fix a Vulnerable Smart Contract You may be asked to identify and fix issues like reentrancy, improper access controls, or unchecked inputs—common in smart contract coding exercises. Build Specific Contract Logic Tasks like implementing a voting system, auction, or multisig wallet test your ability to handle business logic and edge cases securely. Interact with Contracts via Web3.js or Ethers.js Some interviews include frontend interaction—writing scripts to connect wallets, call functions, or read blockchain state. GitHub Projects That Add Value: Custom ERC20/ERC721 with extra features Voting or auction DApp NFT marketplace or multisig wallet Smart contract security fixes (e.g., Ethernaut) These projects not only help you ace Solidity interview code tests but also show real-world skills to employers.