We went the other way, and it was far easier. Actually, our product is an Atlassian add-on, and Atlassian itself went from OnPremise to Cloud. It was, however,

We went the other way, and it was far easier. Actually, our product is an Atlassian add-on, and Atlassian itself went from OnPremise to Cloud. It was, however, a long migration for both Atlassian and the add-on vendors. It was necessary because the market wants to try products withut installing them. Now Atlassian is able to make cloud-level changes to their software: They can use CD, live analytics, mutualized authentication for all tenants, etc. However, their API for cloud addons is, and will be forever, completely different from the API for onpremise addons. It's a major difficulty for the ecosystem. Many vendors extract a .jar that they reuse in both onpremise and cloud addons, but the cloud runtime that connects this .jar to the cloud API is at least as big as the jar itself (because we don't benefit from the host's services such as user management, storage or logging). OnPromise, which we started with, was however easier for us than Cloud. The customers, even enterprise ones (we have about 28 of them) are in charge of Ops, it cuts off half the work for us. And OnPromise is 3x more revenue for us per year, with the downside that it's a one-off, non-recurrent sale by default.