I just evaluated a candidate and flagged it as “no” because they had too many position changes in the last 5 years. Switching jobs is fine, but if you overdo it, you risk looking like a bad investment.
I've been asked that a couple of times and I guess the answers have been satisfactory enough because I've gotten an offer afterwards.
As an interviewer, I've only encountered a couple of incidents where change frequency was enough to concern us. I directly asked both about that. One, I was satisfied with the answers, and he turned out to be a great dev and stuck with us to the bitter end. The other, his answers were "meh" enough that warranted more digging. Sure enough, we discovered there were other positions that were not included in his resume. We passed on him.
This is wrong and misleading in many ways, you should ask people why they left, you should give a chance to those who have good skillset, not based on number of jobs they had. I know a lot of people who worked on contracts, so they had to change employers frequently, and I know a lot of people who were looking for a place, as juniors, to learn from good mentors. It is really hard to find mentors in Startups, and not everybody can make it to big companies. If companies don't invest on their employees, they leave.
But as best I could tell, if we did hire them, we had 12 months tops. Remember, I only have the past record to go on and hiring is the most important and hardest decision to make.
So don’t blame you, but there are reasons - and more than discussed - of why people job hop and understanding that is important.
Only if the potential employer isn't willing to invest in the candidate enough to retain them