Lint
Beginner
An automatic proofreader for design code that flags suspicious patterns before anything is tested.
Novice
A program that reads design code and flags likely mistakes without running it: accidental latches, numbers of mismatched size, unused signals, missing cases. Verilator and Verible are open-source linters.
Expert
Fast enough to run on every code change. Teams keep a fixed set of rules and a reviewed list of exceptions (waivers). A growing waiver file, or a rule switched off for the whole project, is a warning sign, because it also hides every future case of the same problem.