When did you join the Austin office? I'm guessing things changed over time. When I visited there definitely was not a security person (not for the building nor for the Cloudflare suite in the building) and there were no badges. I was able to walk into the Cloudflare office through the unlocked door and walk around inside the office for at least a couple minutes before anyone paid any attention to me (and even that was only because I was trying to get someone's attention to tell me where to go).
Regarding the reception desk, it shouldn't matter if it's a shared building. Unless it's a small company (CF is not), even in shared buildings it's common to have at least one person sitting at a desk in the office suite to act as a gatekeeper and assist visitors, etc.
Regarding the reception desk, it shouldn't matter if it's a shared building. Unless it's a small company (CF is not), even in shared buildings it's common to have at least one person sitting at a desk in the office suite to act as a gatekeeper and assist visitors, etc.