There are a lot of reasons why tenure might be short, but many short tenures, I agree are alarming because people are more lenient when a developer "ramps" up.

There are a lot of reasons why tenure might be short, but many short tenures, I agree are alarming because people are more lenient when a developer "ramps" up. If they are able to stick around and get promoted, that's a strong counter signal. I'm curious, but not to pry the exact details, how long are your tenures on average -- and would you similiarly penalize someone who worked at one company for many years?