I found a site called Progression.fyi that curates a list of "career frameworks," or in other words, the level-progression system of titles that a bunch of tech companies use for their software engineers. It's pretty interesting to peruse.
Several of these companies define what the often nebulous title of Staff Engineer means to them, which I find particularly compelling.
Here are a few companies you've probably heard of, with links to their pages where they define their career progressions for software engineers:
