1. Applied directly, received recruiter's call and followed by email. E-mail was bcc to me so a bit surprise.
2. Arranged interviews, they don't want to adjust to your timings. First interview was with hiring Manager based in US.I took at 7:00AM my time. It was good experience
3. Second and third round of interview was a rush. I got call from recruiter around 10:00PM on Saturday asking for availability for interviews. I have to take second interview 10:00PM and third interview 06:00AM following morning. Second interview was Engineer from US and it was a good experience. Third interviewer was based in Europe but there were two guys. Doing interview without any interest. Continuously keyboard typing and repeating question of each other.
4. Recruiter called me for 4th round of interview with A guy from US. I took interview around 05:00AM of my time. It was not bad interview. He also repeated few questions. But overall was pleasant environment.
5. Recruiter called me to schedule another interview, at this point I have lost interest so I refused to move further.
ZSCaler has good rating on glassdoor but I think they need to improve on the quality of interview process for Singapore.