[ivalm]

> Whereas letting two microservices access the same database tables would probably be frowned upon.

> Nevertheless, sharing the same Kafka topics between microservices seems to be a common thing to do.

I think if it is part of one whole isn’t this fine? You have one service that generates customer facing output, you may have another service that powers analytics/dashboards you may have yet another service that ETLs data into some data mart. Why wouldn’t they touch the same table/subscribe to the same topic (since they just need read-only access to the data)? Genuinely curious what the problem is except for bottleneck/performance; and if it just bottleneck then wouldn’t scaling horizontally solve it?

[jkarneges]

Sure. I believe microservice boundaries are more about development agility rather than scalability. By limiting each microservice to a minimal API surface and a "2 pizza" team, everyone can iterate faster. And if a particular microservice is implemented as multiple sub-services sharing database tables only known by the team in charge, that seems fine.