2009 - After almost 4 years at at a support role at IBM, I wanted a change. They sold me on some architecture role that ended up being about collecting requirements for small SOA projects. After 3 months, my people manager wouldn't let me apply for a job at their Linux Tech Center and said I had to wait at least another year. Plus the director wasn't happy LTC was trying to "steal" other projects' staff and it was unlikely they would even consider. Since I had gotten the maximum performance rating every year, I thought they should be more considerate. Gave a 2-day notice and left. Manager threatened me, saying I would never work for IBM again in my life.
2011 - Team lead was a dick and consistently make me look like a inexperienced fool in front of other teams. He wouldn't touch the infrastructure for fear of breaking it and would constantly fight other teams, trying to hide our issues. I felt it was wrong. One day he refused to acknowledge a ton of errors we were causing and I confronted him. He said I should leave if I wasn't happy. I gave my 30-day notice to our manager. The team lead called me saying I could leave in a week if I wanted (he would talk to my manager to cancel any fines). Before leaving, I updated all our 500+ servers to the latest firmware version that was know to fix a lot of issues. Got thank you notes from other teams for a while.
2012 - project to modernize all servers from aix/VMs/hpux to Linux got cancelled at Motorola after Google bought it. Nothing else to do there and we all know what happened. Stayed 10 months. Nice people but it was like working at a graveyard.
2013 - I guess that IBM manager was wrong after all. Got a job working with Linux at IBM. Left for better pay and more benefits. The team was excellent.
2015 - Left top 5 global food company. They treated us really good but their technology stack was horrendous and they didn't care. I felt it was setting my career back. How would I explain to a recruiter that was working with 10 years old technology? I really miss them though but this is a fast paced industry.
2015 - still here... Lack of clarity around projects is a concern but pay is good, remote work and they are nice people.