Tumblr's longtime CEO David Karp is leaving the company after 10 years. Karp sent out this tweet of a goodbye letter he sent to his former team. Karp's letter reads He is expected to leave by the end of the year and will be replaced
by COO, Jeff D’Onofrio. Karp sold Tumblr to Yahoo in 2013 for $1.1 billion, before it flopped and declined in popularity. Tumblr is now owned by Verizon-owned media conglomerate Oath.