Lyft’s chief operating officer Rex Tibbens plans to step down by the end of the year. The news was first reported by Axios and confirmed by Lyft to TechCrunch.

The ride-sharing company has been busy raising funding, including a recent $1 billion round led by CapitalG that put its post-money valuation at $11 billion, as it reportedly prepares to go public next year.

Tibbens’ planned departure means that Lyft now needs to fill a key leadership role on top of planning an IPO. This news comes almost exactly one year after a report that then-president elect Donald Trump’s transition team was looking at Tibbens as a potential candidate for U.S. Transportation Secretary, which Lyft denied (Trump appointed Elaine Chao to that role).

According to an internal email sent to Lyft employees by co-founders Logan Green and John Zimmer (copied below), Tibbens, who joined the company in 2015 from Amazon, plans to advise companies and spend time with his family next year.