Database Design for Modular Monoliths: Avoiding the Coupling Trap

Mon, 26 Jan 2026 16:22:57 +0000

This post was originally published on my Substack - Backend Engineering Adventures.

Last week, we covered deployment patterns - how to run multiple services from the same codebase. But here’s the thing: you can have perfectly separated Docker containers and still end up with a nightmare when it’s time to extract a module. Why? The database.

This is where most modular monoliths, migration to microservices or service extraction fails. What starts with JOIN payments.transactions ON orders.payment_id = payments.id ends up becoming the coupling hell - suddenly extracting the payments module requires untangling months of accumulated database coupling.

Deploying Modular Monoliths: One Codebase, Multiple Services

Mon, 19 Jan 2026 13:52:23 +0000

This post was originally published on my Substack - Backend Engineering Adventures.

Last week, we talked about the anatomy of modular monoliths and how to structure them. But as you start to do that, issues arise, and one of the common question that you might think about but is afraid to ask out loud is: can have an API and a queue consumer in the same service?

And while you’re a free person, in a free world - meaning that you technically can do this - you likely shouldn’t.

Backend Engineering on biancarosa.com.br

Database Design for Modular Monoliths: Avoiding the Coupling Trap

Deploying Modular Monoliths: One Codebase, Multiple Services