Common Software Architecture Patterns: Layered, Multi‑Layer, Pipe‑Filter, Client‑Server, MVC, Event‑Driven, and Microservices

Software architecture patterns are reusable solutions to recurring design problems; the article covers seven major patterns.

1. Layered Architecture – Divides a system into layers (presentation, business, persistence, database) to separate concerns, improve modularity, and enable independent development. Drawbacks include performance overhead, increased initial cost, and complexity.

2. Multi‑Layer Architecture – Extends layered concepts to distributed environments, grouping logical components into separate tiers (e.g., a J2EE consumer website). It shares similar concerns about cost and complexity.

3. Pipe‑Filter Architecture – Structures a system as a series of processing stages (producer, transformer, tester, consumer) connected by pipelines, ideal for data transformation tasks such as ETL or compilers. Weaknesses are limited suitability for interactive systems and potential performance penalties due to parsing overhead.

4. Client‑Server Architecture – Separates responsibilities between client components that request services and server components that fulfill them, commonly used for online applications like email or banking. Weak points include the server becoming a performance bottleneck and a single point of failure.

5. Model‑View‑Controller (MVC) – Splits an application into Model (data), View (UI), and Controller (mediator) to isolate user‑interface concerns from business logic. It is popular for web and mobile UI development, though it may add unnecessary complexity for simple interfaces.

6. Event‑Driven Architecture – Handles asynchronous events by routing them through queues and dedicated processors, scaling from small to large distributed systems. Weaknesses involve performance and error‑recovery challenges. Example usage: an e‑commerce order service publishes an OrderCreated event, which triggers subsequent services such as credit reservation (or a CreditLimitExceeded event).

7. Microservices Architecture – Decomposes an application into independently deployable services, each with its own API and data store, allowing heterogeneous technologies and team autonomy. Drawbacks include the need for robust monitoring, service orchestration overhead, and higher operational costs. Typical scenarios involve large data‑pipeline workloads where each processing step is a separate microservice.