Startup incubator Y Combinator (YC) has roped in Gmail creator Paul Buchheit as the new managing partner of its main accelerator program.

Buchheit's appointment comes as its current managing partner, Sam Altman, announced plans to reposition himself to focus on three of the four other arms of the incubator.

"I will spend my time across the three investment programs (YC Fellowship, YC Core and YC Continuity) and will also run YC Research until we find someone to run it full time," he wrote.

In his blog post, Altman also announced reshuffling of executives across all five major arms of Y Combinator, the largest incubator in Silicon Valley, which was founded in 2005.

In other announcements, Altman said, App.net CEO Dalton Caldwell is taking over the management of the admission process of the incubator's core program and would also work on engaging with the program's alumni. Meetings.io Founder Denis Mars will work in tandem with Caldwell and will help support the operation.

Altman also announced the appointment of Kirsty Nathoo as the company-wide CFO of YC. Nathoo has past experience working as the VP of finance and operations at YC and as an audit manager at PricewaterhouseCoopers, according to her LinkedIn profile.

Since its establishment, the incubator has helped launch of over 800 companies, including Airbnb, Dropbox, Instacart and Stripe; together, Y Combinator-backed companies reportedly have a valuation of about $30 billion. According to Bloomberg, the incubator's accelerator program invests about $120,000 in each one of the 85 startups it accepts in its program twice every year.