I applied through a recruiter who contacted me on LinkedIn. He interviewed me three times on phone and then I took two assessments online, one with 18 scenario-questions about leadership and the other one was a 2-hour test with four different sections to test personality, IQ, etc. Then again they contacted me to let me know that the hiring managers are interested in my application and invited me for an online interview in which they asked me some questions related to safety. After that they never contacted me again, even though I contacted them four times, once to say thank you for the interview and three times to follow up my application. They've not responded yet which is very impolite and unprofessional. If you don't want to continue with an applicant, it is ok but you'd better let them know of your decision.