If you come to Poland on an entry visa, you can start to work immediately and have a couple of months to change your temporary visa to a residence permit. Be prepared that you may not be able to get an appointment right away with all the immigration complexities like policies, laws and visa opportunities, knowing what to apply or how to apply becomes really confusing. You have to wait weeks or even months for appointments in larger cities. It usually takes several weeks to process the applications and receive the physical residence card, depending on how many authorities have to be involved.