I just quit a job after 9 months. Landed another job. Here is why I quit:
Job involved a relocation that was not going well at all. I really disliked the new area, and missed the old area. I was nervous about the location before moving because I used to live there and didn't like it, but was pressured into making the move by family.
Job presented a hostile work environment. I had a coworker who did many bad things. He grabbed me by the collar and dragged me across the room during stand-up (he wanted me to be able to speak into a microphone so remote people can hear). This caused another coworker to immediately make fun of me for it. This same coworker constantly made inappropriate jokes that made me visibly uncomfortable. He also yelled at me a lot, and called me "weird" for being introverted. I confronted him about the issues and he calmed down/I think he legitimately realized he was being mean and felt bad about it, but I was still very shaken by the whole thing and started sending out my resume at the peak of his abuse. I also recorded all incidents and submitted them to management.
Job had poor engineering quality. This is by far the smallest contributor to my reason for quitting, since it wasn't so bad that I couldn't handle it and there were plenty of opportunities for me to advise how to improve engineering quality. I would've ordinarily stayed at least a year before quitting for this reason.
This job was a post acquisition startup, purchased by a prominent Silicon Valley company you have heard of. I was expecting a similar culture to what I was used to and didn't know it was an acquired startup until after I interviewed - Previous to that, I had worked at Microsoft for three years on Azure. Fortunately, my next job is at a company I know is good because a friend of mine works there.
I'm concerned that this stint will hurt me in the future. I moved back to my old area, but may want to move to Europe in two or three years. I honestly don't know what to say in the interview - I feel like everything about the experience reflects poorly on me. I knew this area wasn't a good fit for me, but I moved anyway - how will future employers trust me to relocate again? If I mention the hostile work environment, will people think I'm just a difficult person?