I see people on various forums (fora?) asking what number of years of experience makes someone "senior". The most common answer I see is 5. It reminds me of this https://i.imgur.com/7sws9p8.jpg
No. Every company has different definitions and different positions have different meanings. Then there is lead manager, product manager, team lead, etc.
Not only that, I've noticed the position titles are different depending on the company. A junior developer in one HR department might be Programmer Analyst in another HR department.
But generally for me, anyone with 1-4 years is junior, 5-9 is mid and 10+ is senior. But that's just my arbitrary definition.
In our field, it's a near meaningless title modifier.
I also wonder if these same people assume everyone else with "senior" in their title has as little experience as they do.