Both of the setups I'm familiar with run multiple application servers on the same "iron" (EC2 clusters), with shared services (database servers, caches, routing

Both of the setups I'm familiar with run multiple application servers on the same "iron" (EC2 clusters), with shared services (database servers, caches, routing, load balancing, etc). Monitoring, backup, ELK, New Relic etc are global, or shared among sets of clusters depending on the specifics. I agree that 12 containerized services per customer seems like a headache. The applications I have experience with run fewer components, and they are mostly shared among clusters.