[alex-lawrence]

I only heard of Nest.js a few weeks ago and haven't had the chance to look it. Therefore, take my reply with a grain of salt.

Libraries and frameworks can help you with different things, but they can also get in your way. If the CQRS module of Nest.js seems useful for a specific scenario, I would give it a try.

CQRS can be implemented in many different ways. Even more, a lot of software is applying this pattern inherently to some extent.

If you separate a software (or a part of it) into a write side and a read side, the two become independent. They both only interact with the synchronization mechanism. Therefore, they are free to use their own set of patterns, libraries and even technologies. Many times, the two parts are operated as individual programs/services and can scale autonomously.

Personally, I never encountered a situation with implementing CQRS where I really would have needed a framework. In fact, I contributed to a Node.js framework for implementing CQRS and Event Sourcing. In hindsight, I think the framework was a mistake and should not even be used.

My book explains how to implement all the concepts, patterns and mechanisms without any third-party code. The goal is not to use the custom code in production, but to understand how everything works.