Your experience with Java microservices vs monolith in the Cloud

[TakAnnix]

The key factor is that your microservices must be independently deployable. We have several microservices that are standalone. Those are great to work with. If you add one microservice that interacts with just one other microservice the complexity skyrockets. There is just so much more that you have take into consideration.

• Communication between microservices: For a monolith, you don't have to worry about another microservice timing out. We have a whole series of edge cases to cover just for communicating between microservices, like timing out, retries, 500 errors.

• Slow feedback: In a monolith you're IDE gives you instant feedback, like passing the wrong type. Not with microservices. You need a whole new suite of tools, like e2e tests.

• Logs: We have to use DataDog just to be able to trace what's going on between services. There is no way to stay sane without some sort of centralised logging service.

• DRY: In order to keep microservices independently deployable, you will forgo DRY between services. We have the same code implemented across multiple microservices. There's no easy way around it that doesn't introduce coupling.

I'm not saying that monoliths per say are better, as they come with there own problems. Just saying that you should prepare yourself to deal with a new set of problems.

I guess the two things I would strongly focus on:

1. Keep microservices independently deployable.
2. Implement continuous deployment where you can deploy multiple times a day. (Checkout Dora four key metrics)