{
  "id": 17388652,
  "title": "Roughly organizing entities, value objects, services, and use cases.",
  "url": "https://urgent.news/2026/10/31/usecase",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-10-31T11:13:25.000Z",
  "source": {
    "name": "Dev.to",
    "slug": "dev-to",
    "url": "https://dev.to/kaziusan/enteiteizhi-obuziekutosabisuusecase-wozatukurizheng-li-131"
  },
  "original_language": "ja",
  "account": "The article discusses software design concepts in the context of Ruby on Rails, specifically Domain-Driven Design (DDD) and Clean Architecture. It explains four key concepts: Entity, Value Object, Service Object, and Use Case. An Entity is an object identified by its ID, such as a User, while a Value Object is defined by its attributes, like a Phone Number. Service Objects contain procedures that don't fit into a specific model, and Use Cases represent a single user action, like registering a case or confirming an order. These concepts help organize business logic and promote a structured approach to software development.",
  "summary": "Well, it's related to Rails, DDD (Domain-Driven Design), and Clean Architecture. Here is a list of terms: - Entities: things identified by ID - Examples: User, Case, Order - Value Objects: things identified by their contents - Examples: Amount, Phone Number, Address, Period - Service Objects: containers for procedures - Examples: Calculating tax, uploading to S3 - Use Cases: one thing a user wants to do - Examples: Registering a case, confirming an order Entities are things identified by ID. A person is the same person even if their last name changes or they move. Conversely, even if there are two people with the same name and age, they are different people. In this way, entities are things identified not by their contents but by their ID (i.e., that they are the same thing). user = User.find(1) user.update!(name: \"Suzuki\") # Even if the name changes, the ID remains 1, and it's still the same user.",
  "key_points": [
    "Entities are core objects identified by unique IDs in Ruby on Rails.",
    "Value objects are defined by attributes, not identity, like a ¥1000 note.",
    "Service objects encapsulate specific actions, orchestrating entities and value objects."
  ],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}