I agree with this approach. the other added benefit is that when they decided to optimize the app by eliminating or tuning queries and utilizing replicas for reads, they ultimately made the app much more performant while possibly reducing complexity. the "squeeze" mindset pays off in the long-run here. the continued optimization over time is infinitely better than adding the complexity of microservices or expanded infrastructure because the latter will simply bury and compound the potential optimizations which could AND SHOULD have been made. squeeze squeeze squeeze until you just can't squeeze any more!