There are at least 2 stages: 1) Airflow certification. Quantori gives you a credit (promocode) to pass Astronomer exam for free. You either get certificate or not. Takes around 45 min. The results are instant. 2) Online test. You are suggested only two time intervals, which you can use to pass the test (you have only one attempt). Takes 1 hour. The results are instant, but it is just a score. So you don't know if you pass or not. Both tests are not easy at all.