Who is a blockchain developer?

Blockchain developer is a software development engineer who is capable of designing and implementing smart contracts or dApps.

Typically this requires a specific skillset such as understanding of core principles of cryptography, blockchain design principles, decentralized storage, Merkle Tree, consensus algorithms etc as well as hands-on experience with specific programming languages and frameworks. In Ethereum ecosystem, for example, developers shall be able to program smart contracts in Solidity programming language, use Web3.js framework, understand how to work with Geth, how to run an Ethereum node, carry out mining etc. They should also understand the main principles around ERC token standards and know most common standards such as ERC-20.