Part 135 or stay being an instructor?
 

Hello, I just got done with a phone interview with a 135 op, I’m curious to know if I should take this (assuming if I get the job) or continue being a CFI till I reach my time. I’m currently sitting at 680 hours. The ultimate goal is to go to the airlines.

In the old days 135 would make you more competitive for regionals. Today that's not necessary.

The 135 experience would make you a better pilot.

But if you bust a checkride, that will haunt your career forever. So I'd definitely research their training program.