I feel like including Digital Ocean is not quite in the spirit of the list lol. AWS is "on-prem" also, then.

Also Level3

Level3 is not there on the list.

The cloud is someone else’s prem

Doesn't twitter have its own datacenters too? But they also use GCP, not sure how they split the load

It was my understanding that they are trying to take things in house but that they currently rely heavily on GCP.

Each company have different motivations. For e.g. Basecamp moved to save cost.

Working in Enterprise, I can share hybrid model works best for multinational. If they are going into new geography, where local laws restrict data transfer across national boundaries, having a cloud provider with local data centers is the easiest and quickest way to launch.

Mentioning Digital Ocean and Cloudflare as on-prem companies makes as much sense as listing AWS and Google. Digital Ocean is one of the world's top ten largest cloud providers and Cloudflare is one of the world's largest CDNs.

Depends on what you find interesting, but almost all banks and insurance companies run their own data center. Often multiple, for redundancy reasons

Does Wikimedia count? They're a non-profit but on-prem

I think so. It isn't about $$ that they are making. More of smaller/less obvious companies that take this path.

If you have a reference, please submit a PR.

I opened a PR adding Automattic to the list. They run WordPress.com and Tumblr and all their infrastructure is in 30 private datacenters across 6 continents.

Thanks for your contribution. Always interesting to learn about such companies.