Tbh, the best way to do this is likely the hybrid model adopted by, e.g., gitlab rails and Grafana Loki etc.. air usually let's the operator select if they want

Tbh, the best way to do this is likely the hybrid model adopted by, e.g., gitlab rails and Grafana Loki etc.. air usually let's the operator select if they want to run as a monolith, service with multiple components where some are instanced, and full micro service mode. For small deployments you can just use the monolith and be done with a single "service" while you still have the ability to scale out for large deployments. This gets even better when they allow you to do an in between where one component does A and B while only C is handled by micro services.