Hiring a surveyor is unusual in that most of the work happens where you cannot see it. The visible part, a crew on your property for a few hours, sits between two longer stretches of research and drafting.
Before anybody arrives
The surveyor researches the record: your deed, the deeds of the properties around you, recorded plats, and whatever earlier surveys exist. Boundaries are established from the record and the evidence on the ground together, so this part is not administrative overhead. It is the survey.
On a property with clean recent records this is quick. On old rural land with vague calls and no recent work, it is the bulk of the job, and it is the main reason two properties of the same size can be priced very differently.
On the day
A crew arrives with a total station or GPS equipment and works the perimeter, looking for existing monuments: iron rods, pipes, or marks set by earlier surveyors. Recovering an existing monument is better than setting a new one, because the older mark usually carries more weight in establishing where the line has been understood to run.
They will need access to the boundary, which sometimes means the neighbouring side of it. Clearing brush along the line beforehand genuinely speeds things up.
What gets left behind
Corners are marked, typically with capped iron rods, often with a flag or stake so you can see them. Those marks are the physical output. Leave them where they are: moving a monument is both expensive to fix and, in most states, an offence.
What you receive
A drawing, signed and sealed by the licensed surveyor, showing the boundary and whatever the survey was commissioned to show. How long that takes after the field work varies with the firm and the complexity, and it is a fair question to ask when you get the quote.
Two things worth asking up front
How long after the field work you will have the drawing, and whether the price includes setting corners or only locating them. Both are common sources of surprise and both are easy to answer in advance.