It is unprofessional. Everyone, please!, you gotta be careful and not drain yourself with them.
First I got a general call for like 30 minutes where the recruiter was an hour late, then another call for like 30 minutes asking "Critical and Analytical Questions" which he was also late for an hour. Then, I was told that I should go for an online coding challenge for Python which I did and passed.
After that, the recruiter told me that there will two rounds, if I pass them, I will have "meet & greet" with their client (Facebook) and will sign the contract. I have then went for round one which was about 2 weeks after their first call, he was almost 1.5 hrs late for this video interview. I managed it professionally and acted like nothing happened. Few days later, the recruiter called me stating that it was wonderful and I have passed round 1, I have to go for round 2 now which is collaborative coding challenge. If I pass round 2, I will sign my contract. I prepared myself for the coding challenge, but the interviewer wasn't their and after waiting for almost 50 mins, I called the recruiter and they told me, it seems he is in holiday. Again, I acted professional and they rescheduled the interview for "Saturday". I did the coding and the recruiter called me within days that I passed it and I just have to go to their client location and meet the team. This process so far took around 2 months. I then booked tickets to their client's location (which was in another EU country - Zurich, all my money and nothing was reimbursed), and after getting myself ready, I receive an email from them one day earlier that it will be rescheduled because the team traveled. I discovered that the email title was changed from "Software Engineer" to "Lab Technician". After like 2 weeks, I had a video interview instead and discovered that it wasn't just signing the contract but an assessment as well which the recruiter previously told me that I already got the job. After the video interview, I was told that within couple days they will let me know the outcome. I waited for days, weeks, months, no one ever spoke to me. I tried multiple times to talk with the recruiter but he never answered.