Zscaler

Zscaler’s Zero Trust Exchange is a distributed cloud proxy platform that inspects internet- and private-app-bound traffic in-line, brokering direct, identity-verified connections between users and specific applications rather than placing users on a routable network segment. This inverts the traditional firewall/VPN model: instead of granting network-level access and then trying to restrict it, Zscaler never puts the user on the corporate network at all, which structurally eliminates lateral-movement paths that a compromised VPN session would otherwise expose.

The architecture is built on data centers Zscaler operates worldwide, doing SSL/TLS inspection, sandboxing, DLP, and CASB functions at the edge rather than backhauling traffic to on-prem appliances. This has made it one of the primary vendors credited with popularizing the Zero Trust Network Access (ZTNA) and Security Service Edge (SSE) categories as VPN replacements.

As of its FY2025 10-K, Zscaler reported more than 9,400 customers, including roughly 40% of the Forbes Global 2000 and over 45% of the Fortune 500, with trailing twelve-month revenue around $3.17B — among the strongest adoption and growth signals of any pure-play network-security vendor covered here.