Zscaler is company on the cutting edge of cloud security, and the employees here are extremely intelligent and informed on both the product, the industry, and what's important to the customers. The interview process was difficult, but very fair. That said, it was one of the best I've been a part of. The HR manager was excellent, and I was provided insights into next steps, timing, etc. throughout the process.
The interview process consisted of 4 stages. 1) 1:1 screening with the HR manager, 2) 1:1 screening with the hiring manager, 3) face to face panel interview at HQ including individuals from various divisions within the organization, 4) 1:1 with VP.
The interview process requires that candidates do their homework. It's expected that you will have a general understanding of the overall Zscaler value proposition, and how this solves the various issues that the industry is experiencing with the movement to remote users/sites and cloud migration. The panel interview is a chance to showcase your presentation skills, your ability to display your understanding of the value proposition and various product sets, and how you respond to difficult questions/scenarios. The panel discussion can go on for a number of hours, and is tremendously helpful for both sides of the table to ask questions to ensure a cultural fit.