I also previously worked for Microsoft (Azure Active Directory). We took code quality very seriously. All new features required at least 80% code coverage from tests before commit (not a particularly high bar, but a pragmatic one). New features also required a test plan + review covering stress/perf, unit, integration, & system tests. Many features required threat models which were reviewed with the security team.

Progress/bugs were reviewed weekly at ship room. Live site issues were reviewed the next morning (involving the relevant on-call engineers).

So as with any large company which isn't a monoculture, things vary from team to team.

Also, calling them "M$" in 2016?