Where should I position the patch panel and network switch?

A very common arrangement is to put the patch panel immediately above or below the switch.

That keeps patch leads short, makes ports easier to trace and avoids sending twenty-four little Ethernet excursions around the cabinet before they finally reach a switch sitting several U away.

It isn’t mandatory, though. Your layout also needs to account for cable management, equipment depth, ventilation, power connections and where heavier equipment is best placed.

Think of the rack as a complete system rather than a sequence of individually convenient mounting decisions.