Reddit's CEO Yishan Wong is resigning, and departed co-founder Alexis Ohanian is coming back. In a blog post, Ohanian said that he would be returning to Reddit as executive chairman; The New York Times reports that he will be taking control of the site's marketing, strategy, and communications. Wong, meanwhile, will temporarily be replaced by former second-in-command Ellen Pao. In his post, Ohanian said that "mobile, user experience, and community tools are on the top of our list" going forward. He wasn't specific about why Wong left, but Y Combinator president and Reddit advisor Sam Altman explained more on his blog, where he also indicates that he was very briefly Reddit CEO:

Last week, Yishan Wong resigned from reddit. The reason was a disagreement with the board about a new office (location and amount of money to spend on a lease). To be clear, though, we didn’t ask or suggest that he resign — he decided to when we didn’t approve the new office plan.

Wong is the second major Reddit executive to depart in the past month. Erik Martin, who had been with the site since 2008, announced his resignation as general manager in mid-October. Martin often acted as company spokesperson, a role it now seems that Ohanian might be at least partly taking on. Ohanian also noted that the company is gaining a new executive as well: Reddit Secret Santa founder Dan McComas, who joined Reddit in an acquisition three years ago and will now serve as VP of product.

Ohanian helped launch Reddit in 2005, but he left the site in 2010, remaining until now only in an advisory capacity. (Among other things, in the interim, he's hosted our series Small Empires.) Wong, a long-time Reddit member, stepped up as CEO in 2012, a year after Reddit left its parent company Conde Nast. Not long before leaving, Wong described Reddit as "the government of a new type of community," defending its laissez-faire principles after a series of leaked celebrity nudes were publicized on the site. While Altman seems to have laid out the reasons for his departure clearly, the Times also says that Wong had made some people at Reddit uncomfortable by publicly excoriating a former employee the month before his departure.

Pao, meanwhile, has overseen Reddit's operations and mobile development, including the acquisition of third-party app Alien Blue and the launch of an official AMA app. She joined Reddit in mid-2013 as strategic partnerships manager after a year as a "formal and informal" advisor, and was previously a junior partner at venture capital company Kleiner Perkins, before filing a gender discrimination case against the firm. That case is still ongoing, with a trial expected next year. Though we still don't know who will ultimately be stepping up as CEO, Ohanian said that Pao "has already shown tremendous capability and poise over the last two years" at Reddit.