The application itself may be same-day at a port of entry, but gathering experience letters and having an offer letter properly drafted commonly takes six to eight weeks. A petition adds processing time that should be checked at the time.
Old employers are the slow part
In a career built across several properties, the qualifying experience may sit with employers who no longer exist in the same form, whose managers have moved on, and whose records are held by a corporate office elsewhere. Chasing three letters can take a month. In parallel, the offer letter usually needs revision: human-resources departments write to internal templates, and the first draft rarely uses the language the listed profession requires.
Two or three rounds are normal. If a petition route is chosen, add current USCIS processing time, checked at the point of filing rather than assumed, and note that premium handling where available shortens adjudication and not preparation. Working back from a start date, six to eight weeks is a realistic minimum and ten is more comfortable.