Prescreening Questions to Ask Blockchain Smart Contract Developer

What experience do you have with smart contract development on various blockchain platforms?

When hiring a smart contract developer, it's crucial to understand the breadth of their experience. Have they solely worked on Ethereum, or do they have experience with other platforms like Hyperledger, EOS, or Binance Smart Chain? The more diverse their experience, the better they'll be at adapting to different project requirements.

Can you explain the differences between Ethereum and other smart contract platforms like Hyperledger, EOS, or Binance Smart Chain?

A proficient developer should be able to articulate the distinctions between these platforms. Whether it's the consensus algorithms, transaction speeds, or the programming languages used, understanding these differences can provide insights into their adaptability and depth of knowledge.

How do you ensure the security of your smart contracts?

Security is paramount in smart contract development. Ask the candidate about their security practices. Do they follow best practices like checks for integer overflow, use of secure libraries, and avoidance of known pitfalls? Their answer will reflect their competence in protecting your project from vulnerabilities.

Have you ever conducted a smart contract audit? If so, what tools and methodologies did you use?

Conducting audits is a skill that separates novice developers from seasoned professionals. Inquire about the tools they use, such as MythX, Echidna, or Slither, and the methodologies they follow. This can help you gauge their attention to detail and thoroughness in ensuring code reliability.

Can you describe a project where you developed and deployed a smart contract?

Real-world experience speaks volumes. Ask the candidate to walk you through a project they’ve worked on, including the challenges they faced and how they overcame them. This can provide insights into their problem-solving abilities and project management skills.

How do you handle upgrades and migrations of smart contracts?

Smart contracts are often immutable, making upgrades and migrations a complex task. Discover their strategies for managing these processes. Do they use proxy contracts, for example? Understanding their approach can help you assess their long-term thinking and foresight.

What is your experience with Solidity programming language?

Solidity is the most popular language for Ethereum smart contracts. Delve into their hands-on experience with Solidity, ensuring they're proficient and comfortable coding in this language. This will determine their readiness for Ethereum-based projects.

Have you ever worked with other smart contract languages like Vyper or Rust? If so, can you describe your experience?

While Solidity is dominant, other languages like Vyper and Rust are gaining traction. Knowing if they've worked with these can reveal their versatility and willingness to explore and adapt to new technologies.

Can you explain the concept of gas fees and how it affects smart contract execution?

Gas fees are an integral part of Ethereum transactions. A developer must understand how these fees work, how they can be optimized, and their impact on contract execution. This will give you an idea of their efficiency and cost-awareness.

What strategies do you use for optimizing gas costs in your contracts?

Optimizing gas costs is an art. Ask about their methods, such as using efficient data structures, minimizing storage usage, and optimizing loops. This can showcase their proficiency in writing cost-effective and efficient code.

How familiar are you with decentralized finance (DeFi)? Have you developed any DeFi applications?

DeFi is a booming sector in blockchain. If they're experienced with DeFi, they’ll likely be familiar with its unique challenges and opportunities. This experience can be immensely valuable if your project touches on financial applications.

What is your approach to testing smart contracts?

Testing is crucial. Find out how they ensure their code works as intended. Do they use tools like Truffle, Hardhat, or Ganache? Their testing methodology will reflect their commitment to delivering robust and reliable contracts.

Can you describe a challenging problem you faced in smart contract development and how you solved it?

Challenges are par for the course in development. Their experiences in overcoming tough problems can shed light on their perseverance, ingenuity, and problem-solving skills.

What tools do you use for debugging and deploying smart contracts?

Debugging and deployment tools are essential. Inquire about their preferred tools and platforms, such as Remix, Hardhat, or Truffle. This will help you understand their workflow and familiarity with the development ecosystem.

How do you handle private data within a public blockchain?

Privacy is a major concern. Ask about their approach to handling private data. Do they use techniques like zero-knowledge proofs or off-chain solutions? Their answers will reflect their understanding of privacy and security in blockchain.

Are you familiar with decentralized storage solutions like IPFS or Filecoin?

Decentralized storage complements blockchain. Knowledge of solutions like IPFS or Filecoin indicates their ability to handle data storage in a decentralized manner, enhancing the overall architecture of your project.

What is your experience with token standards like ERC-20, ERC-721, or ERC-1155?

Token standards are pivotal in Ethereum. Familiarity with ERC-20, ERC-721, or ERC-1155 shows their expertise in implementing these standards, which is crucial for projects involving tokens or NFTs.

Can you explain the concept of oracles and how you have integrated them into your smart contracts?

Oracles bridge the gap between blockchain and the real world. If they’ve worked with oracles, it means they can create contracts that interact with external data, enhancing the functionality and utility of your project.

How do you stay updated with the latest developments in blockchain technology?

Blockchain is a fast-evolving field. Ask how they stay current with the latest trends, updates, and technologies. Whether it’s through online courses, forums, or reading research papers, their dedication to continuous learning is key.

What experience do you have with smart contract security best practices or frameworks?

Security is non-negotiable. Ask about their familiarity with security best practices and frameworks like OpenZeppelin. This will help ensure they have the necessary knowledge to build secure smart contracts for your project.