So even if you've been working at a company for a year, if you're from outside the EU they still by law must advertise the position for a month in a half?
No, not in my experience at least.
The KVR told me that you must go through the process of at least checking that no one available from the EU can perform your job, so you are not taking a job away from an equally qualified unemployed EU citizen, but the job does not have to be re-advertised if you are still employed.
This "process" took one day for me.