It wasn't anything special. We used Java because it's what we knew, with a mix of spring and some home grown framework stuff that we've developed over the last

It wasn't anything special. We used Java because it's what we knew, with a mix of spring and some home grown framework stuff that we've developed over the last 10 years. MySQL over Postgres because that's what we had experience with at the time. Redis as both a cache and ephemeral store.