Multi Platform Apps Multi Platform

Multi-Platform Feature Development Workflow

Build and deploy the same feature consistently across web, mobile, and desktop platforms using API-first architecture and parallel implementation strategies.

[Extended thinking: This workflow orchestrates multiple specialized agents to ensure feature parity across platforms while maintaining platform-specific optimizations. The coordination strategy emphasizes shared contracts and parallel development with regular synchronization points. By establishing API contracts and data models upfront, teams can work independently while ensuring consistency. The workflow benefits include faster time-to-market, reduced integration issues, and maintainable cross-platform codebases.]

Use this skill when

• Working on multi-platform feature development workflow tasks or workflows
• Needing guidance, best practices, or checklists for multi-platform feature development workflow

Do not use this skill when

• The task is unrelated to multi-platform feature development workflow
• You need a different domain or tool outside this scope

Instructions

• Clarify goals, constraints, and required inputs.
• Apply relevant best practices and validate outcomes.
• Provide actionable steps and verification.
• If detailed examples are required, open resources/implementation-playbook.md.

Phase 1: Architecture and API Design (Sequential)

1. Define Feature Requirements and API Contracts

• Use Task tool with subagent_type="backend-architect"
• Prompt: "Design the API contract for feature: $ARGUMENTS. Create OpenAPI 3.1 specification with:
  • RESTful endpoints with proper HTTP methods and status codes
  • GraphQL schema if applicable for complex data queries
  • WebSocket events for real-time features
  • Request/response schemas with validation rules
  • Authentication and authorization requirements
  • Rate limiting and caching strategies
  • Error response formats and codes Define shared data models that all platforms will consume."
• Expected output: Complete API specification, data models, and integration guidelines

2. Design System and UI/UX Consistency

• Use Task tool with subagent_type="ui-ux-designer"
• Prompt: "Create cross-platform design system for feature using API spec: [previous output]. Include:
  • Component specifications for each platform (Material Design, iOS HIG, Fluent)
  • Responsive layouts for web (mobile-first approach)
  • Native patterns for iOS (SwiftUI) and Android (Material You)
  • Desktop-specific considerations (keyboard shortcuts, window management)
  • Accessibility requirements (WCAG 2.2 Level AA)
  • Dark/light theme specifications
  • Animation and transition guidelines"
• Context from previous: API endpoints, data structures, authentication flows
• Expected output: Design system documentation, component library specs, platform guidelines

3. Shared Business Logic Architecture

• Use Task tool with subagent_type="comprehensive-review::architect-review"
• Prompt: "Design shared business logic architecture for cross-platform feature. Define:
  • Core domain models and entities (platform-agnostic)
  • Business rules and validation logic
  • State management patterns (MVI/Redux/BLoC)
  • Caching and offline strategies
  • Error handling and retry policies
  • Platform-specific adapter patterns Consider Kotlin Multiplatform for mobile or TypeScript for web/desktop sharing."
• Context from previous: API contracts, data models, UI requirements
• Expected output: Shared code architecture, platform abstraction layers, implementation guide

Phase 2: Parallel Platform Implementation

4a. Web Implementation (React/Next.js)

• Use Task tool with subagent_type="frontend-developer"
• Prompt: "Implement web version of feature using:
  • React 18+ with Next.js 14+ App Router
  • TypeScript for type safety
  • TanStack Query for API integration: [API spec]
  • Zustand/Redux Toolkit for state management
  • Tailwind CSS with design system: [design specs]
  • Progressive Web App capabilities
  • SSR/SSG optimization where appropriate
  • Web vitals optimization (LCP < 2.5s, FID < 100ms) Follow shared business logic: [architecture doc]"
• Context from previous: API contracts, design system, shared logic patterns
• Expected output: Complete web implementation with tests

4b. iOS Implementation (SwiftUI)

• Use Task tool with subagent_type="ios-developer"
• Prompt: "Implement iOS version using:
  • SwiftUI with iOS 17+ features
  • Swift 5.9+ with async/await
  • URLSession with Combine for API: [API spec]
  • Core Data/SwiftData for persistence
  • Design system compliance: [iOS HIG specs]
  • Widget extensions if applicable
  • Platform-specific features (Face ID, Haptics, Live Activities)
  • Testable MVVM architecture Follow shared patterns: [architecture doc]"
• Context from previous: API contracts, iOS design guidelines, shared models
• Expected output: Native iOS implementation with unit/UI tests

4c. Android Implementati