For when you do not need a meeting. You need someone senior to actually read the thing.
Send me an architecture diagram, a design doc, a repo, or a written description of what you are planning. Within 48 hours you get back a written review covering: the two or three decisions I would change and why, the failure modes I would expect at ten times your current load, what I would measure before shipping, and what I would leave alone.
No calendar coordination and no timezone problem. Useful before a build starts, before a vendor decision, or before you take an architecture to a board that will ask harder questions than your team did.