Tech skills top out at senior level, but companies want to be able to pay some senior engineers more than average. Without affecting the senior level range.
It’s also form of title inflation and way to seem like advancing in career ladder.
Some companies have to have a growth track, so it’s a way to give senior level people some form of goal to attain. It’s mostly HR process than any engineering principle.
It's not the only way to do things, but it's quite possible to have role and skills for a staff engineer be a strict superset of senior engineer.
Do you not think there's any difference between a senior who might be working well at a high level but just within one company, and a senior who might be doing work at the very top of their entire field worldwide?
But, principal, staff, lead, and senior are all pretty much the same tech skill level. Promotions to higher levels are mostly based on subjective attributes, like leadership qualities, personable qualities, innovation qualities, etc.
It’s mostly HR process to keep more rungs in individual contributor career track. Way to retain high performance engineers in the career ladder, and show that there are more opportunities for advancement.
I don't really understand that... you think someone at the level of a distinguished engineer, maybe something like a Turing Award winner or someone who has invented fundamental concepts in the field, is 'pretty much the same tech skill level' as someone just promoted from mid-level developer doing routine development work?
I also don't see why it's 'title inflation' to recognise the difference between those two?
You are right. But if the pay keeps going up (and responsibilities too), there are many people who are honestly happy with that deal.