Valuation: $925 million
Total raised to date: $220.04 million
Year founded: 2011
HQ: San Francisco
What it does: Fastly calls itself an "edge cloud platform." It helps large websites work faster by moving data and apps closer to their users.
Why it's hot: Fastly has come on strong in this well-established market (also known as a Content Delivery Network) and already powers sites such as Airbnb, GitHub, Alaska Airlines, Pinterest, Vimeo, The Guardian, and The New York Times.
It reportedly broke the $100 million revenue mark in 2017 and this year raised funding that included backing by the investment arm of telecom giant Deutsche Telekom.