I use Oracle Cloud and AWS, but I am more into AWS. At my current organization and in my previous organization, I have worked on AWS. Only in one organization, Credit Suisse, I worked on Oracle Cloud.

We had previously employed IBM. IBM's support proved to be excessively costly, leading us to opt for Amazon.

We did also work with VMware and Microsoft. We wanted something with better ease of use. 

We previously used Microsoft Azure.

I have only used this solution.

The change was mainly because of the CDN servers.

We also use Azure.

This was the first implementation, we did not switch from any other product.