Both people sit in one initial application, so the couple's planning date is driven by the slower half — whichever spouse has a document still outstanding or a question still open. Published material describes the process in weeks, but that is descriptive, not a promise, and the final stage depends on visa availability.
Plan around the couple's shared dates
Work out which household commitments are genuinely fixed — a lease ending, a job notice period, a business sale — and which can move. Keep both passports valid well beyond any expected travel, and keep both spouses available for an interview or a document request rather than scheduling long trips. If one partner intends to keep working abroad for a period, raise that with a qualified adviser before residence begins.
Agree in advance who speaks for the household. Requests for documents and scheduling arrive without notice and often carry short deadlines, so decide which spouse monitors correspondence, where documents are kept, and what happens when that person is travelling. A process with two applicants generates twice the correspondence and exactly the same capacity to be missed.
Hypothetical example: a couple nominates a single inbox, keeps a shared index of every document already obtained, and reviews it monthly, which turns a request for a certified translation into a two-day task rather than a fortnight spent hunting for the original. None of that shortens the process, but it removes the delays the household would otherwise create for itself.