I worked in the cloud at MS roughly 7 years ago, and Bing was very different from anything else. The MS cloud services were a total mess. I mean, as in hard to overstate how bad. In contrast, Bing was a well-oiled machine. Simple build, simple deploy, simple devops, simple test, very consistent processes across all of their teams.

At the time, Azure was a joke (partly due to the fact that the initial teams were headed up by ex Office devs with no cloud experience, if I remember correctly). But Azure was cannibalizing the Bing team pretty hard. I hear that strategy worked and that Azure is in much more capable hands now.