I am a hiring manager

It's the same on the candidate side. I know when I interview, what it'll take to bring me on board depends a lot on the company, the team, and what the position looks like. For something I absolutely want to be a part of, because all of the above are incredible, it's not going to take as much in compensation as a place that's not perfect in one aspect or another, but is otherwise nice at the right price. But I won't know where the company sits on that spectrum until after the interview.

In my experience (and I've been on both sides plenty of times) - There's always a budget. Call it a band, a range, whatever, the budget exists, and in many jurisdictions the world (and even within different states in the US) over you have to specify what that budget is for any given position. Some places are better than others, like settings a ridiculous range that tells you nothing (100k - 300k like your example) useful, to be fair. Usually, a job post will be for a specific role. A senior, principal, medior, junior, L9, ABC123, doesn't matter, a rank is usually attached to the job description. At least from what I've seen (and I'm sure this part does vary a lot company to company and role by role, but IME it's pretty rigid with tiny allowances for things like mediors switching to a senior position and stuff like that), the business is pretty adamant on hiring for the advertised role , …