Implementation of a Design System as Standardized Development Guidelines for Consistent iOS User Interface Development: A Case Study of the Jasa Perantara Application

The increasing complexity of mobile application development creates challenges in maintaining consistent user interface (UI) implementation, particularly when design specifications are translated into software code by different developers. This study aims to implement a Design System as standardized development guidelines for the iOS version of the Jasa Perantara mobile application using SwiftUI. The study employed an implementation-oriented qualitative case study approach consisting of four stages: existing design analysis, Design System development, Design System implementation, and implementation verification. The analysis examined eight representative application screens and identified recurring UI elements requiring standardization. The developed Design System incorporated five reusable UI components, eleven standardized typography styles based on Apple’s Human Interface Guidelines, five color token categories, and three button variants. The Design System was subsequently integrated into the Jasa Perantara iOS application, with four application screens migrated to standardized components and three iOS developers involved in the implementation. Verification results indicated improved consistency between design specifications and software implementation, along with a reduction of approximately 30–40% in UI-related testing and bug-fixing activities. The findings demonstrate that a Design System can function not only as a reusable UI component library but also as a practical development guideline and single source of truth that reduces implementation ambiguity, supports collaboration between designers and developers, and improves software maintainability. The study concludes that integrating a Design System directly into a SwiftUI-based production application provides an effective approach for standardizing iOS interface development, enhancing consistency, reducing repetitive implementation effort, supporting sustainable application maintenance, and strengthening development coordination across teams and future application iterations