Handles UI interactions
Backend & Runtime / Knowledge library
Layered Architecture
Organizes responsibilities into ordered layers with controlled dependencies
Why learn Layered Architecture?
It separates presentation, application, domain, and infrastructure concerns
The problem it solves
It prevents every component from depending directly on every implementation detail
Where it came from
Layered Architecture is a software design pattern that organizes responsibilities into ordered layers with controlled dependencies. Its guarantees and tradeoffs depend on the concrete implementation and operating context.
Build your understanding
Work through these exercises in order. Try the task before opening a reference.
- Define Layered Architecture and distinguish it from a neighboring concept.
- Choose a realistic task where Layered Architecture is appropriate.
- Identify a failure mode caused by misusing Layered Architecture.
- Interpret a small design or result involving Layered Architecture.
- Explain one tradeoff or limitation of Layered Architecture.
Documentation and sources
- Patterns of Enterprise Application Architecture (martinfowler.com)
Connect the ideas
Explore next
Real World Example
Modularizing Logistics Orchestration
A regional logistics firm managing complex supply chain routing and warehouse inventory.
The business problem
Tight coupling between database access logic and business rules caused cascading failures whenever the underlying schema changed, leading to high maintenance costs.
How this topic solves it
Implementing a Layered Architecture organizes responsibilities into ordered layers with controlled dependencies, ensuring the domain logic remains agnostic of data storage details.
- Define a Presentation Layer to handle user requests without direct database access.
- Establish a Service Layer to coordinate business operations and define the application boundary.
- Implement a Domain Layer to encapsulate core business rules and data models.
- Create a Data Source Layer to handle persistence, isolating the database schema from the rest of the application.
Read from top to bottom; each layer only communicates with the layer directly below it.
Coordinates operations
Business rules and logic
Database persistence
- Presentation → requests → Service Layer
- Service Layer → executes → Domain Layer
- Domain Layer → persists → Data Source
Expected business outcome
Improved maintainability and testability, as changes to the database schema are now confined to the Data Source Layer without impacting business logic.
Limitations and checks
A potential limitation is the overhead of mapping data between layers, which can lead to redundant code; this is checked by monitoring the complexity of object transformation logic between the Domain and Data Source layers.