> From a startup engineer's POV this is a non issue - a 18-24 month tenure is pretty standard.
This assumes there's another job waiting for you at the end of it. Raises and job offers remaining plentiful at the same time funding is drying up would require quite specific circumstances to continue - namely, that none of the companies driving today's offers depended on cheap money to get to where they are. If a substantial group of them did, there may not be much of a next round.
That said, a lot of what we see right now appears to just be crowd-following, a lot of what really happens will depend on if businesses see substantial customer exits, not just funding tightening. But if, say, there's a big enough startup crunch to hit AWS's bottom line in such a large way that they start laying people off, suddenly you can start seeing potential feedback loops pushing salaries down and difficulty of finding a job up.