I was part of a group that inherited a really buggy service platform, maybe a dozen services, 3 generations of most services still around, no logging, nothing. The previous team had kept some foreign engineers on-call and never taken shifts - and there were daily pages, absurd processes to "fix" things, etc.

In about two weeks of putting engineers on call for their own services, most of the major problems were fixed.

It's easy to write buggy software when you aren't the one who gets called at 2am to fix it. Once you start being responsible for your software, the urge to take shortcuts really evaporates. On the other hand, a team that is not responsible for their output will always cut corners - it's just the way it goes.