On: First .dev Domains Go Live

[jhgg]

How does a company who owns a trademark get a domain early like Slack and Github did?

[CydeWeys → jhgg]

You need to get your trademark into the Trademark Clearinghouse: https://newgtlds.icann.org/en/about/trademark-clearinghouse

Then you use a corporate domain name registrar to register it during the sunrise phase.