Every founder I talk to has the same quiet dream get the company to SF, be in the room and the same quiet dread: the visa maze. O-1 "extraordinary ability" evidence you may or may not have yet, E-2 if you happen to have treaty-country money, the H-1B lottery that's basically a coin flip, and lawyer quotes that make your eyes water.
If you've done it, or you're mid-attempt: what path did you take, what blindsided you, and what do you wish someone had told you before you started?