ILLUMIO

Andrew Rubin and PJ Kirner were cybersecurity veterans who realized the industry was spending billions defending network perimeters (firewalls, intrusion detection) while ignoring what happened after an attacker got inside. In 2013, they founded Illumio to pioneer microsegmentation — creating internal security boundaries within a network.

Instead of one castle wall, you get thousands of internal walls. If an attacker compromises one server, they can't reach the next one.

SaaS subscriptions. Enterprises pay annual fees based on the number of workloads (servers, containers, endpoints) protected.

Illumio's software creates a real-time map of all application communications and then enforces segmentation policies. The platform works across on-premise data centers, cloud environments, and hybrid setups.

Illumio Segmentation — its core product, which maps how applications talk to each other and blocks everything that should not be talking, across data centers, clouds and endpoints (it brings together what used to be sold as Illumio Core, CloudSecure and Endpoint). Illumio Insights — AI-driven cloud threat detection that spots attacks moving inside a network and helps contain them.

Zero Trust momentum. The cybersecurity industry shifted toward "Zero Trust" architecture (trust nothing, verify everything).

Microsegmentation is a core component of Zero Trust. As CISOs adopted Zero Trust frameworks, Illumio became a natural purchase.

They also benefited from high-profile breaches (Colonial Pipeline, SolarWinds) that proved perimeter security wasn't enough.

Market education and the long wait for an exit. Microsegmentation is technically complex, and many organizations struggle to roll it out without breaking their applications.

Illumio has to convince security teams the effort is worth it. Competition has intensified from Akamai (which bought Guardicore), from the big firewall vendors, and from newer rivals like Zero Networks.

Its last funding round was in 2021, at the peak of the market, so any future IPO or sale has to justify that $2.75 billion price.

Andreessen Horowitz, General Catalyst and Formation 8 backed the early rounds. BlackRock and Accel led the $100 million Series C in 2015, and J.P.

Morgan Asset Management led the $125 million Series D in 2017. Thoma Bravo led the $225 million Series F in 2021, with Franklin Templeton, Hamilton Lane and Blue Owl joining, at a $2.75 billion valuation.