JSS Database location.. Localhost or remote???

One server per service has always been my design. That way I can control how much resources each box needs.

If you end up going clustered service, then you don't want the load of the web app and database plus all the other web apps hitting that box at once.

Second @franton

If your install base is growing at all over the next year or two, then I would recommend getting the separation of Tomcat and MySQL done and out of the way. You get all the benefits of service separation and in theory, if you are growing, then you can bring up more Tomcat servers fairly quickly without hurting what is already in production.

I recommend the Jamf 350 course highly if possible...they will teach you this concept as well as help you to plan scaling the right way.

Depends on how large your environment is. If your device count is only in the hundreds of devices total and you don't have a lot of external integrations into Jamf then you're probably fine with Tomcat and database sharing a beefy server, especially if your environment isn't going to grow significantly (still good practice to have the database on a separate server as @franton said though).

Otherwise I'd be looking at a dedicated server for the Jamf database, that's the first thing that should be done to scale Jamf for improved performance.

If you're never going to grow past a couple hundred devices, then one server is fine. If you're going to do more, then it's best to start with different servers and prepare for a clustered environment.