Castles in the Cloud

Greylock’s interactive project maps multiple data points of the cloud computing ecosystem — and plots new opportunities for success.

Building a Winning Business in the Shadow of AWS, GCP, and Azure.

Among the great technology platform shifts of modern times, perhaps none have revolutionized industries at the speed, impact, and rate of innovation as significantly as cloud computing. But AWS, Google and Microsoft have not conquered the entirety of the cloud market. This is why we’ve begun a new undertaking at Greylock: A comprehensive, interactive project to map the cloud ecosystem: Castles in the Cloud.

In The New Moats we looked at the power of the major cloud incumbents – Amazon, Google, Microsoft — and the “Castles in the Cloud” they have built. The goal for every startup is to build a sustainable business model that can assault these incumbent castle walls while simultaneously building their own defensive moats.

Numerous opportunities still exist to push the boundaries of what the technology can accomplish. This project helps identify areas where startups can and may win.

Our intention is to make this a dynamic and collaborative project with the cloud startup community. We invite the community to help identify and submit successful challengers to the Big 3 and share how or why they are winning.



The number of markets Big 3 Cloud services are categorized into by Greylock, based on the functionalities and end users they serve



Number of different offerings and capabilities offered by the Big 3 Cloud providers within each given market



Total services offered by Big 3 Cloud providers


Emerging Startups

All companies valued ~$500M-$1B competing with Big Cloud services, as well as select startups valued under $500M

Source: Methodology



Companies worth +$1B competing with Big Cloud services

Source: Methodology


VC Funding

Total VC funding into the cloud ecosystem in the US in 2019-2022, according to Pitchbook.

Source: Methodology