Senior designers …
… Have ten or more years of professional practice in the discipline, not 1 or 2 or 3 or 4 or 5 or … not 10 years of time passing or 10 years in some other discipline or …
* I first noticed in the early 90’s that some firms were charging out junior designers as seniors, profitability in a down economy, maybe this is better than the alternative, and that the title ‘Intermediate Designer’ had disappered from use. Ten years a big span of time to title/charge-out one with ‘Junior’.