Cloudflare began as a side project that tracked spammers. Matthew Prince and Lee Holloway built that tool, Project Honey Pot, years before they built a company. Then Prince told a business school classmate, Michelle Zatlyn, about it. She saw a bigger idea: stop the attacks as well as track them. Cloudflare's network sat between websites and their visitors. It sped up pages and blocked attacks before they landed. By September 2019, more than 20 million websites, apps, and domains used it, many on the free plan.

From Honey Pot to Network

Prince, Holloway, and Zatlyn founded Cloudflare in July 2009, while Prince and Zatlyn were students at Harvard Business School. They wrote the business plan in class. Holloway built the first working version. The bet was to give the basic service away to small sites, learn from all that traffic, and sell bigger plans to large companies. Holloway stepped down in 2015 after he fell ill with frontotemporal dementia.

Fifteen Dollars on Day One

Cloudflare priced at $15 a share on September 12, 2019. It began trading on the NYSE the next day under the ticker NET. The stock rose as much as 30 percent during the day and closed at $18, up 20 percent. The offering raised $525 million. Cloudflare kept adding products on top of the same network that served its free customers. It is still public on the NYSE.

Cover: Mist Rising at Sunset in the Catskills, Sanford Robinson Gifford. Art Institute of Chicago, public domain. Chosen for sunlight flaring through clouds.