KakaoPage Shares Case Study on Frontend Architecture Design Based on SOLID Principles

A KakaoPage developer shared a practical case study on applying SOLID principles to frontend architecture. The author emphasized that SOLID is not merely a set of coding rules but a core value in architecture design linked to the organization's communication structure, specifically explaining how each principle is implemented in a React environment.

Component Design via SRP and OCP

SRP (Single Responsibility Principle) means separating components by 'responsibility' rather than 'behavior'. The author advises that setting component boundaries according to internal communication flows among planning, design, and development can minimize side effects. For OCP (Open/Closed Principle), the team adopted Apple's Compositional Layout pattern, structuring it into Section, Group, and Item hierarchies to allow extension without modifying existing code when API specifications change.

Practical Application of LSP, ISP, and DIP

LSP (Liskov Substitution Principle) violations occur when defined interfaces and actual implementations are inconsistent, which is a major cause of increased debugging difficulty. The author points out the need to avoid adding unintended logic to components like ApiErrorBoundary.

ISP (Interface Segregation Principle) and DIP (Dependency Inversion Principle) are utilized during component composition. Data fetching logic was separated into a Fetcher component using React's children prop, and the Compound Pattern was applied to configure TicketInfo components to receive only the necessary props. This inverted dependencies and ensured testability.

Architecture Expansion via BFF and GraphQL

The article also covers how SOLID principles are applied when introducing BFF (Backend-For Frontend) and GraphQL beyond the frontend domain. Introducing a BFF layer allows for excluding unnecessary data from the client's perspective (ISP) and providing interfaces independent of server implementation changes (DIP). Additionally, leveraging GraphQL's Fragment feature to support polymorphism creates a structure that satisfies OCP across multiple platforms (Web, iOS, Android).