I don't see how these guys can think about MAU/DAU to assess DB load and sizing without talking about the rest of the app/arch details. Wouldn't ops/time be more agnostic?
Agreed, number of active users cannot make sense as a generic unit across systems...
I have 2 systems where in the first (route optimization platform), 1 user would, as part of just a normal 10 minute session:
- read ~100MB from the database
- utilize 100% of 32-core machine CPU (and 64GB of RAM)
- resulting in thousands of writes to the database
- and side-effect processing (analytics, webhooks etc)
Over a course of a day, it would likely be ~10x for that single user.
In the other system - appointment scheduling - 1 user would, in 1 day, read ~1MB of data from the database, and make 2-3 writes from a single action, with maybe 1 email triggered.
Can make sense if it's about loading and showing not-too-complicated data, but no intensive computations. Then you can compare roughly similar applications
