Used to be U.S. passports were produced on site by embassies and consulates, for a very quick turn-around. Now they're all produced in the States (except for short-validity emergency passports).
In most countries for renewal you just mail your old passport and the application to the nearest American embassy or consulate, which then sends it electronically to the passport factory in the U.S.
The factory couriers it back to the embassy or consulate which then mails it back to you.
In normal times, it's a two-week or so process, but real slow after Covid.
Cost is US$130, plus local mail postage.
-@zif
Nicer to use local mail or local pickup. The two week wait I suppose is OK if it's backwards and forwards to the USA.
I seem to remember several years ago it took about 4 weeks for me to get my UK passport delivered to Hungary. I resent the commercial international courier costs. I expect with Brexit, they will be held up in Customs or confiscated.
If they printed them locally, it could be a couple of days or even same day for simple cases. It's not like the equipment costs that much and the admin must be trivial.
A US Air Force guy I used to know told me they did all the Embassy deliveries so it's not like they need to use commercial services anyway.