Musk issues the blue check: Are you with him or against him?

Elon Musk says Twitter is a software and servers company at its heart and has asked employees to decide by Thursday evening if they want to remain a part of the business, according to an email sent by the company’s new owner to its remaining staff.

Musk wrote that employees “will need to be extremely hardcore” to build “a breakthrough Twitter 2.0” and that long hours at high intensity will be needed for success.

Musk, who also heads Tesla and SpaceX, said Twitter will be much more engineering-driven, with employees who write “great code” comprising the majority of the team.