Steven Bartlett has built one of the world’s biggest podcasts on the idea that the right people, obsessively managed, make the machine. Now four of those people have walked out the door. The star host of “The Diary of a CEO” has lost four core staffers in five months, Business Insider reported.

The exits are not junior. One is Jack Sylvester, who calls himself a co-founder of the show and built its YouTube presence to more than 18 million subscribers. Also gone: executive producer Jem Erith, trailers director Anthony Smith, and Grace Miller, whose job title was “head of failure and experimentation.”

Former colleagues did not undersell them. One described Sylvester and Erith as the “inner circle” behind the “heavy lifting” of the podcast. “They’re the reason it gets delivered twice a week,” another said of the four.

A friendly framing, and a bigger picture

Everyone is being nice about it. Bartlett’s company, FlightStory, said the departures were planned over almost a year and that the staff left on good terms. All four posted warm goodbyes. “I owe Steve more than I could ever put into words,” Sylvester wrote, while admitting he did not know what was next.