Yul gives direct access to EVM opcodes inside an `assembly` block. It is useful for reading arbitrary storage slots, cheap memory manipulation and proxy fallbacks — and it disables the compiler's safety checks.
assembly {
let v := sload(slot)
mstore(0x00, v)
return(0x00, 0x20)
}Use it sparingly, comment every line, and keep a high-level reference implementation to test against.