Big changes afoot at Hyperloop One. On Friday, it was revealed that Brogan BamBrogan, the company’s co-founder and chief technology officer, would be stepping down. The news comes at the end of a big month for the firm, which is working to develop Elon Musk’s Hyperloop idea into reality.

Taking over BamBrogan’s role will be Josh Giegel. “Hyperloop One is pleased to announce that Josh Giegel has been promoted to President of Engineering and appointed to the Board of Directors. Josh has been a valued engineering leader as co-founder and SVP of Engineering since the company’s inception,” the company said in a statement to Recode. “Co-founder and CTO Brogan BamBrogan has decided to take a step back from Hyperloop One. We appreciate everything that he has done to put us on the path to creating the world’s first Hyperloop.”

Recode also reports that earlier this week, chief legal officer Afshin Pishevar and assistant general counsel David Pendergast were removed from their positions.

Hyperloop One has made great progress towards the goal of a transport system that could manage San Francisco to Los Angeles in 30 minutes. Led by some of SpaceX’s best minds, the company completed its first propulsion test back in May. The test, demonstrated in front of an audience in Las Vegas, only lasted five seconds but received a standing ovation.

Last month, BamBrogan spoke with Science Friday and outlined Hyperloop One’s future plans. The system has the potential to act as a giant, interconnected transit system across the globe, going underwater and underground at super high speeds.