[2arrs2ells]

Twitter, Atlassian, Eventbrite, Okta & Dropbox, are all pubic & in SF. Facebook, Google, Microsoft (Github) have a sizeable SF presence.

[shanev]

Atlassian is based in Sydney, Australia.

[andrewbinstock]

Their original US office (and I believe still their biggest in the US) is in SF.

[paxys]

Square and Salesforce as well

[cgy1]

Splunk too.

[hawaiianbrah]

Also Microsoft (Xamarin)

[lemoncucumber]

Square too.