The licence usually sets the timeline rather than the immigration step. Start credential verification and the state application as early as possible, because those are the parts nobody can accelerate.
Sequence around the slowest step
The immigration step can be quick if the port-of-entry route is used and the packet is complete, or it takes as long as adjudication if a petition is filed. Neither is usually the binding constraint for a licensed profession. Credential verification services and state boards work on their own schedules, and documents from a university registrar or a provincial regulator can take weeks to arrive. Working backwards from the employer's desired start date usually shows that licensing has to begin months earlier. The other reason to sequence this way is that a licence application refused or delayed for an unexpected reason changes the whole plan, and it is better to learn that before resigning a position in Barriere.
Hypothetical example: A Canadian computer systems analyst is asked to begin a payroll-conversion project immediately after a new system goes live. The employer should first obtain the final duty schedule, degree records, and any needed evaluation, then select the admission or petition sequence that fits the real start date. The signed project plan settles whether the date is genuine. Do not let a software launch create pressure to begin productive work before the proper status exists; a delayed start is easier to explain than unauthorized work.