As an up-and-coming manager at Microsoft, Michael Wallent had a reputation for being a tough boss—at times, a bit too tough. He had joined the company in 1996 and advanced quickly; by 1999 he was overseeing a team of 300 engineers who worked on developing Internet Explorer. Like Microsoft’s founder, Bill Gates, who met with Wallent to review his team’s work each quarter, Wallent focused on data and facts, not employees’ feelings, and was known for delivering withering criticism in product-review sessions. His typical comments: “This is stupid.” “This is wrong.” “This is what you need to do.” Debra Chrapaty, his former boss (who’s now at Cisco), says, “Michael was known to be aggressive, a little bit condescending, harsh—he had an arrogant engineering mind-set.”

A version of this article appeared in the November 2010 issue of Harvard Business Review.