Application Architecture

Module 2

Clean and Onion Architecture

Concentric rings with dependencies pointing inward: what that actually buys, how clean and onion differ, and the three ways teams implement the diagram without getting the benefit.

31 min2 lessons
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What you will be able to do

  • State the dependency rule and explain what crossing it costs.
  • Describe the responsibilities of entities, use cases, adapters and frameworks.
  • Explain how data crosses a ring boundary without dragging inner types outward.
  • Diagnose the anaemic-domain and mapping-explosion failures.
  • Decide when the rings are worth their ceremony and when a flatter structure serves better.

  1. 01Rings, and the Rule That Points Inward

    Clean and onion architecture are the same structure under two names: business rules at the centre, everything replaceable at the edge, and source dependencies that only ever point inward.

  2. 02What It Costs, and Three Ways Teams Get Nothing For It

    The rings are expensive. This lesson prices them honestly, then examines the anaemic domain, the mapping explosion, and rings applied uniformly to code that has no rules.

Clean and Onion Architecture

6 questions · pass at 75%