Most corporate event checklists cover the obvious: venue, catering, AV. The details that actually cause problems on the day are usually smaller and less glamorous.
Badge printing and registration flow: if you're expecting more than 100 guests, test your check-in process end-to-end before the event, not on the morning of.
Power and connectivity: confirm the venue's outlet locations and Wi-Fi capacity match your actual equipment needs, especially for hybrid or livestreamed sessions.
Signage and wayfinding: guests get lost in venues they've never visited. Clear directional signage reduces the number of times your staff has to redirect people manually.
A single point of contact on-site who isn't also presenting or hosting — someone whose only job that day is solving problems as they come up.