Standard interview procedure as others described below:
1. Resume Application and phone screening
2. Numerical Assessment & Verbal Assessment like SHL test
3. 1st round interview focus on personal background check
4. Group Discussion Center
I finished procedure 1 to 3 and it took me about 6 weeks, it had been a long time. And after the first interview with two supervisors, I received a phone call one day which mentioned I passed the interview and was invited to next step Group Discussion Center.
From then on I got no notification from BAT and even didn't know what's going on. It's not responsible for applicant especially waiting for a long time, too ridiculous.