In 2016, CEO and co-founder Matthew Prince told the BBC about the beginnings of Cloudflare.
Cloudflare's roots go back to 2004 when Mr Prince and Cloudflare co-founder Lee Holloway were working on a computer industry project they called Honey Pot.
The idea was that people with websites signed up for free, to install software which then tracked people who sent unsolicited emails.
Five years later Mr Prince was doing a Master of Business Administration (MBA) at Harvard Business School, and the project was far from his mind, when he got an unexpected phone call from the US Department of Homeland Security asking him about the information he had gathered on attacks.
Mr Prince recalls: "They said 'do you have any idea how valuable the data you have is? Is there any way you would sell us that data?'.
"I added up the cost of running it, multiplied it by ten, and said 'how about $20,000 (£15,000)?'.
"It felt like a lot of money. That cheque showed up so fast."
Mr Prince, who has a degree in computer science, adds: "I was telling the story to Michelle Zatlyn, one of my classmates, and she said, 'if they'll pay for it, other people will pay for it'."
And so the idea for Cloudflare was born, with Ms Zatlyn as its third co-founder.