I think we also should be more clear with "10 Users". What does he/she mean? What do we mean?
It could be 10 users that each views a few web pages once every month or it could be 10 heavy users for an internal system that uses the system most of the working day and creates thousands of calls per user to the system each day.
It is as a lot of people have mentioned also very different with information that can be easily cached and things like monetary transactions where you don't want to see old data in reads and therefore often can't cache or use read replica db.
For systems with heavy users I have seen the need to use a few servers even with just 1000 - 2000 users. For a web system the same can happen if you have 1000 users active on the site at the same time (within a minute or so).
It could be 10 users that each views a few web pages once every month or it could be 10 heavy users for an internal system that uses the system most of the working day and creates thousands of calls per user to the system each day.
It is as a lot of people have mentioned also very different with information that can be easily cached and things like monetary transactions where you don't want to see old data in reads and therefore often can't cache or use read replica db.
For systems with heavy users I have seen the need to use a few servers even with just 1000 - 2000 users. For a web system the same can happen if you have 1000 users active on the site at the same time (within a minute or so).