If you were at a place for five years, got two promotions, and shipped three products while you were there? Strong evidence.
If you were at five places for 9-18 months at a time with several six month gaps interspersed? Not evidence of absence, but that’s absence of evidence to me. (Immediately, I’m assuming several of those gaps might be flameouts.)
I would be wary of anyone job hopping every 9-12 months or even two years. For one reason, they dont stick around long enough to see the long term effect of their work and learn from it. So even if there is no 6 months break, thats still a yellow flag to me.
That’s better, because it suggests four times out of four, the decision to leave and timing was yours rather than “seven times out of nine [four listed], the change was employer-initiated”.
None of these are signals that I rely on as binary go/no-go gates; the main point was “just because you got other employers to pay you for a short while, that’s not standalone evidence that you can deliver business value through working software”.
I don’t believe in jobs-for-life, “putting in your time”, “paying your dues”, “never quit before 2 years”, or other nonsense advice, but if you’ve never had a long stint at a place, at minimum you’ve never seen the pain from your decisions 24 months prior play out and the maximum negative case is far worse.
And, furthermore, if you've never worked anyplace longer than a year or two--and I really want to hire someone longer term--it would be pretty silly for me to assume I'm so special that you'll stick around. My loss perhaps. But that would certainly factor into my thinking.
IME (and this certainly is what's happened in my career, but I've seen it in many), this is usually a lack of mobility options or undercompensation. Few enough quality workers leave places where there are opportunities to grow and (not or) where yearly raises are in the ballpark of the salary delta from moving to a new position. And if you fall into the trap of working for a bunch of startups, you also get the fun "aaaand sometimes startups just explode from underneath you" effect, too.
For most of the folks I've worked with, it's the case that if they take a job and they're not learning something, they're not going to stay long. And if they take a job and the choices are "stay here, even if they enjoy it" and "take a 15% compensation bump that will ripple through the rest of their career", it would be foolish not to go for the latter.
The places that understand that retaining people takes effort are less rare than they used to be, but they don't grow on trees. If you want to hire someone longer term, I hope you're putting the money, and the investment in that worker, on the table.
That's all fair. At the same time, there tends to be a certain amount of gripe-age with any job and some people are more inclined to try to work through it and others are more inclined to start job-hunting. Which is perfectly fine but, if it's a persistent pattern, I probably won't hire you.
To be clear, I'm talking about a persistent pattern. Even those of us with fairly long-term employment (~10 year stints) in general often have one or two short stints for various reasons. E.g. dot-bomb in my case although the job wasn't a great fit anyway.
If you were at five places for 9-18 months at a time with several six month gaps interspersed? Not evidence of absence, but that’s absence of evidence to me. (Immediately, I’m assuming several of those gaps might be flameouts.)