While there are no particular exams as such that one has to appear for, you might required to show your IELTS result to your employer. You should also make sure that you pass college/university with stellar grades so that your employer has a gist of how capable you are. Other than that, some jobs may have screenings and verification that you need to stay prepared for. Moreover, ensure that you have a valid post-study work permit that allows you to work full-time. If your employer asks you to immigrate abroad, you might have to apply for a work visa, which has its own formalities.