Their background was impressive enough that they where able to raise venture funding for their start-up.

Many times they have built or worked on something technically impressive, that became big & well known (Google Maps, Facebook timeline, Founding engineer at start-up with Billion dollar+ valuation).

I think the intention was to say that they are "rockstars" in their own head with however way they choose to define it.

I could be wrong but that's my take.