CQRS as part of not CQRS system


I’m newbie in cqrs but I like theory and want to try it in practice.

I have already ecommerce system with price, product catalog, inventory sub-systems but which was not done using cqrs.

And my team are going to implement cart module with checkout and place order functionality.

We are going to call all these sub-systems to orchestrate our logic.

So is it fine to implement just this little part – maintain cart, create order and verify payment(s) using cars?

I will appreciate if someone can share his experience.

Also, it’s not clear for me how I should handle calling to this third party sync systems (most of them provide Public Sync REST API only) like checking inventory, adding type of payment or do authorization payment.

Can I do call to third party directly from aggregate or should I try to wrap and put some layer to emulate like I still work with command/events (for example for checking inventory before add item to cart or by place order)?


*cars = cqrs :slight_smile:

Hi Guys,

Sorry if my question is too noob question or off topic here, I will try to ask at the DDD/CQRS group.


Hi Evgeniy,

sorry for the lacking response to your question. These are busy times.
I noticed your post on the ddd/cqrs, and that it has been answered there.

My short answer would be: yes, it’s possible and in fact very normal. In the end, not all systems can (and should) be CQRS.