On March 20th, Michael Seibel announced on X that after working at Y Combinator (YC) for over 12 years, he will transition to the role of "honorary partner." Y Combinator CEO Garry Tan also separately shared this news in a company blog post, emphasizing Seibel's long history of collaboration with the accelerator. Seibel initially joined YC as a founder and participated twice in the program - once with the streaming startup Justin.TV and another time with the streaming app Socialcam. Subsequently, Seibel served as a group partner, managing director, and CEO of the YC accelerator. It is worth noting that Seibel has recently stepped back into a less operational group partner role. In a blog post from YC last year, he wrote that he was preparing to "transition my leadership responsibilities" and that this would "officially take effect" after the completion of the accelerator's winter startup batch.