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I can’t speak from experience, but the article you linked seems to make sense. Rails appears to have very little to do with object oriented programming, except

I can’t speak from experience, but the article you linked seems to make sense. Rails appears to have very little to do with object oriented programming, except as an implementation detail. My point is that although Evans strongly recommends OOP for DDD in the blue book, it’s not a requirement. If the first design phase of DDD, where you sit down with the domain experts, you might discover that what you are building is really just a CRUD app. Then it’s probably wise to actually use a CRUD framework, Rails or otherwise. You’re still using DDD, and you’re not even going against the grain or missing out on framework features. When you make your database your model you delegate “decoupling from persistence” to the authors of your RDBMS. They have already decoupled it for you in that you’re not opening files and writing data, your INSERT statement is just stating facts about your domain. I’ve explored the pattern of putting the entire domain model in the database in the form of constraints, triggers and queries that return JSON. The controllers just map URLs to queries, validate the input and just pass the result of the query to the client without looking at it. It’s extremely powerful and productive. You never have to think about N+1. It’s more like logic programming than anything else. The downside is that SQL and associated tools aren’t terribly ergonomic, and it’s hard to find developers who are comfortable working like that.

regularfry 5y ago
I think part of the point is that if you are a Rails shop first, then trying to strap DDD on is only rarely going to work. If you are a "right tools for the job" shop who decide to do DDD as a primary tool, then there might be cases where it is what you choose.
- Tabular-Iceberg 5y ago
  Even if you are a Rails shop first, you can use DDD to determine if it's wise to take on the project in the first place. If it turns out that the domain cannot be expressed as a CRUD app, maybe refer the client to someone else. Then you will officially have used Rails with DDD, even if you haven't written a single line of Rails code for the project. Much of DDD is really tech independent, and takes place before a single line of code is written. This is probably also where it's the most important. You're going to have to learn the domain first or the project will be a world of pain regardless of what architecture you choose.

regularfry 5y ago

I think part of the point is that if you are a Rails shop first, then trying to strap DDD on is only rarely going to work. If you are a "right tools for the job" shop who decide to do DDD as a primary tool, then there might be cases where it is what you choose.

Tabular-Iceberg 5y ago
Even if you are a Rails shop first, you can use DDD to determine if it's wise to take on the project in the first place. If it turns out that the domain cannot be expressed as a CRUD app, maybe refer the client to someone else. Then you will officially have used Rails with DDD, even if you haven't written a single line of Rails code for the project. Much of DDD is really tech independent, and takes place before a single line of code is written. This is probably also where it's the most important. You're going to have to learn the domain first or the project will be a world of pain regardless of what architecture you choose.