Mark Zuckerberg and Dropbox CEO Have Been ‘Close Friends’ For Years. Here Are 7 Other Top Tech Exec Friendships. Posted byAvery Hartmans March 12, 2020March 14, 2020 Leave a comment on Mark Zuckerberg and Dropbox CEO Have Been ‘Close Friends’ For Years. Here Are 7 Other Top Tech Exec Friendships. Silicon Valley might be competitive, but it also appears to be a breeding ground for friendships among its famous execs.