With the new data privacy policies worldwide, we are trying to make sure we host our Magento stores (and its customer database) in the appropriate location, however, we still need to keep the benefit of having 1 Magento backend, which will make it easier to handle and maintain.
Can we have 1 Magento backend with multiple stores and have these stores' data hosted on different servers?
we are using Magento community edition.
This will not be possible as for one backend there will be one database and one set of tables storing user information. You can't spread the different stores' user data across different databases.
Yes it is possible, but the complexity would almost certainly far outweigh your budget, our consulting partner lets us use their clusters and effectively do the same, we have an admin server as the backend with datasets replicated across web servers and multiple Galera databases in a cluster.
There is nothing stopping the web servers, file storage, and database instance being in separate locations fed from a single admin instance, separate countries is one thing, cross continent will induce heavy latency, the performance would be unclear but we are running at 200ms TTFB and 95%/98% page load performance for products and categories, basically it would be a similar approach to CDN 'edges'.
The complexity would be how to separate the data from a business perspective, but that would require a deep-dive analysis as it would be company, site, requirement, specific.