Originally Posted by KingCanute

Your first post - welcome!

There is no obvious way of knowing which gate you will arrive at in advance. Any notionally pre-allocated gate may change anyway if the inbound flight is delayed en route (or if the previous aircraft from that gate gets held up). I have had bus gates for all aircraft types at DOH except A380 (and no doubt someone will be along soon to detail their experience disembarking down steps from one those at some remote part of the airfield)

Yes, a separate bus.

The very overwhelming majority of all arriving passengers will pass through transfer security, so if you assume that's what will happen you will most likely be correct. I can’t remember arriving on a flight myself that bypassed transfer security since way before covid (including flights from LHR).

And an advantage of a bus gate arrival is being dropped right by the central security area at the terminal and not having to walk from a high numbered gate. Even with the airport bus tour it can sometimes be as quick as a contact gate in churning you out into the post-security areas.

Probably best not to overthink it and just deal with wherever you arrive on the day. But if you find new airport transfers stressful you can prebook the Al Maha service, which offers various levels of meet and greet packages (for a fee).