What is Solidity?
Solidity is the dominant language for writing smart contracts on Ethereum and other EVM chains. It compiles to EVM bytecode and is the baseline skill for onchain engineering.
In practice
Solidity work is judged on security discipline as much as language fluency: reentrancy, access control, integer handling, and upgrade patterns. The usual toolchain is Foundry or Hardhat with heavy test coverage, and public audited contracts are the strongest portfolio evidence.