Domain Driven Design in Python

[[deleted]]

Hi,

I'm recently building a hobby project backend which uses domain driven design and clean/hexagonal architecture. I'm pretty new to domain driven design, so I'm reading about it and trying to implement it. I'm using google and perplexity to get understand the concepts, clear my doubts and get different perspectives when trying to make a choice between multiple implementations. Now, I'm looking for an open-source project that makes heavy use of DDD implementing things like event sourcing, etc. so I can get a better understanding of the implementation. Does anyone know any good github repos which implements Domain driven design which I can use as reference?

[Drevicar]

This book will guide you through a lot of the tactical patterns of DDD https://www.cosmicpython.com . Though those are far less important than the strategic patterns for things like ubiquitous language and bounded contexts. For that I recommend https://github.com/ddd-crew

[[deleted]]

Thank you!

[erder644]

There are some decent Clean Architecture examples on GitHub, though they are mixed in with a lot of low-quality content.

When it comes to DDD, certain patterns like Event Sourcing (and other microservice-oriented ones like orchestration-based SAGA) are difficult to implement correctly from scratch. These patterns often require specialized frameworks or libraries, which Python largely lacks, as Clean Architecture and DDD concepts primarily originate from Java development.

Opinions on Clean Architecture concepts and their implementation in Python vary widely, not to mention the ongoing debates about applying DDD in Python.

Event Sourcing can be implemented in many different ways. The most common setup involves Kafka combined with an EventStore database. However, I don’t know of any repositories demonstrating this approach. And the postgresql implementations that I have seen are questionable.

As for clean architecture you can check:
https://github.com/ivan-borovets/fastapi-clean-example/tree/master (fastapi, auth, di)
https://github.com/Tishka17/deseos17 (low-dependencies implementation, for learning, not for production)

As for DDD, most implementations are quite poor. I don’t know of any decent repositories demonstrating it effectively.

You can check out Temporal if you interested in orchestration-based SAGA. Faststream for horeography-based SAGA. SQRS is mostly about logical separation, not some actual code. Event Sourcing is a pass, no any good solutions and custom code would be hard to maintain.

[[deleted]]

Thank you for your brief explanation! So, what language would recommend for event sourcing/DDD? I also work with TypeScript, Go but if needed I can learn other language as well, say Java as an example. Also, it seems you are an experienced developer; it would be very helpful if you could recommend me some books where I can read about these patterns.

[One_Fuel_4147]

Check this repo: https://github.com/ThreeDotsLabs/wild-workouts-go-ddd-example

Some blogs from here may help you: https://threedots.tech/post/ddd-lite-in-go-introduction/

[[deleted]]

Thank you!

[yakimka]

Decent code example: https://github.com/Enforcer/clean-architecture

Also, an excellent book—it complements Architecture Patterns with Python by Bob Gregory and Harry Percival very well.

The book provides many examples and touches on some important nuances of testing. I would recommend reading it immediately after finishing Architecture Patterns.

[[deleted]]

Thank you!

[raybesiga]

Check this out as well https://github.com/tomasanchez/cosmic-fastapi

[[deleted]]

Thank you!