As I build out my infrastructure for Adama (my real-time SaaS for state machines), I'm leaning hard into a monolithic design. The key reason is to minimize cost and maximize performance.

For instance, comparing Adama to the services needed to build similar experiences offered by AWS has interesting results. Adama costs 97% less than AWS ( https://www.adama-platform.com/2022/03/18/progress-on-new-da... ), and a key thing is that the microservice approach is amenable to metering every interaction which scales linear to demand whilst a monolithic approaches condenses compute and memory.