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I've been with my current company for a little over half a decade now. We were acquired by a larger company, and we've gone through most of the headache of the overhaul of IT, human resources, payroll, etc. We're a mostly Linux-centric business (in our particular office, and a few others), but the new parent company's IT department has imposed a mandate: Only Windows machines anywhere in the company.
This means that we'll gradually have to move everything that uses Linux into a virtual machine or container (servers, employee laptops, etc). We've already tested this out for several of our use cases, and the loss in performance is massive. My team and I have voiced our concerns, but we are effectively being stonewalled with "make it work in Windows"). This has caused us to already miss two deadlines when we've never missed a single one in the past five years, and I'm basically being reprimanded for this setback.
I think at this point it's time to start looking for new work, as my team and I can't get our jobs done efficiently with the virtual machine software crashing routinely, the huge performance reduction, etc. What is a good thing to tell interviewers when asking why I left? I'm trying to put a good "spin" on "my employer destroyed our development process" without whining or attacking my former employer, which is never a good thing to do during an interview.
Also, these reprimands could eventually turn into a "performance improvement plan" (PIP, i.e. "we're getting ready to fire you legally without a valid reason), and I'd rather just get on with my life than pursue legal action against my employer for wrongful dismissal.