Interviewing people for blockchain roles? Applying for blockchain jobs? These are some of the top interview questions right now.
- What is a blockchain?
- Why are blockchains often referred to as distributed ledger technologies (DLT)?
- What is proof of work/proof of stake/proof of elapsed time etc.?
- What is a consensus algorithm and why is it useful in blockchain?
- Explain the common consensus algorithms (e.g. Paxos, Raft, Tangeroa, PBFT, RBFT, BFTsmart etc)
- What is hashing/hash functions and how are they used in blockchain?
- Give me an overview of Bitcoin.
- What is mining? How does it work in Bitcoin?
- What is the difference between Bitcoin and Ethereum?
- What are smart contracts? Do you know a smart contract language (Solidity / Serpent / Vyper) ?
- How does Hyperledger Fabric work?
- What are some common privacy modes in blockchain (e.g. encrypted on chain data, channels in hyperledger fabric, R3 Corda privacy model)
- What is the difference between a public blockchain and private/consortium blockchains? Pros and cons?
- What is an ICO?
- What is a token?
- What is an ERC20 contract?
- What is a Merkle tree/trie and how is it used in blockchain?
- Explain how public / private digital signatures work.
- Explain the difference between symmetric and asymmetric key encryption?
- How does Diffie Hellman key exchange work in SSL? What is it used for?
- What scalability and throughput challenges are there with blockchain? What solutions would you suggest?
