Multi Platform Apps Multi Platform

1---
2name: multi-platform-apps-multi-platform
3description: "Build and deploy the same feature consistently across web, mobile, and desktop platforms using API-first architecture and parallel implementation strategies."
4---
5 
6# Multi-Platform Feature Development Workflow
7 
8Build and deploy the same feature consistently across web, mobile, and desktop platforms using API-first architecture and parallel implementation strategies.
9 
10[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.]
11 
12## Use this skill when
13 
14- Working on multi-platform feature development workflow tasks or workflows
15- Needing guidance, best practices, or checklists for multi-platform feature development workflow
16 
17## Do not use this skill when
18 
19- The task is unrelated to multi-platform feature development workflow
20- You need a different domain or tool outside this scope
21 
22## Instructions
23 
24- Clarify goals, constraints, and required inputs.
25- Apply relevant best practices and validate outcomes.
26- Provide actionable steps and verification.
27- If detailed examples are required, open `resources/implementation-playbook.md`.
28 
29## Phase 1: Architecture and API Design (Sequential)
30 
31### 1. Define Feature Requirements and API Contracts
32- Use Task tool with subagent_type="backend-architect"
33- Prompt: "Design the API contract for feature: $ARGUMENTS. Create OpenAPI 3.1 specification with:
34  - RESTful endpoints with proper HTTP methods and status codes
35  - GraphQL schema if applicable for complex data queries
36  - WebSocket events for real-time features
37  - Request/response schemas with validation rules
38  - Authentication and authorization requirements
39  - Rate limiting and caching strategies
40  - Error response formats and codes
41  Define shared data models that all platforms will consume."
42- Expected output: Complete API specification, data models, and integration guidelines
43 
44### 2. Design System and UI/UX Consistency
45- Use Task tool with subagent_type="ui-ux-designer"
46- Prompt: "Create cross-platform design system for feature using API spec: [previous output]. Include:
47  - Component specifications for each platform (Material Design, iOS HIG, Fluent)
48  - Responsive layouts for web (mobile-first approach)
49  - Native patterns for iOS (SwiftUI) and Android (Material You)
50  - Desktop-specific considerations (keyboard shortcuts, window management)
51  - Accessibility requirements (WCAG 2.2 Level AA)
52  - Dark/light theme specifications
53  - Animation and transition guidelines"
54- Context from previous: API endpoints, data structures, authentication flows
55- Expected output: Design system documentation, component library specs, platform guidelines
56 
57### 3. Shared Business Logic Architecture
58- Use Task tool with subagent_type="comprehensive-review::architect-review"
59- Prompt: "Design shared business logic architecture for cross-platform feature. Define:
60  - Core domain models and entities (platform-agnostic)
61  - Business rules and validation logic
62  - State management patterns (MVI/Redux/BLoC)
63  - Caching and offline strategies
64  - Error handling and retry policies
65  - Platform-specific adapter patterns
66  Consider Kotlin Multiplatform for mobile or TypeScript for web/desktop sharing."
67- Context from previous: API contracts, data models, UI requirements
68- Expected output: Shared code architecture, platform abstraction layers, implementation guide
69 
70## Phase 2: Parallel Platform Implementation
71 
72### 4a. Web Implementation (React/Next.js)
73- Use Task tool with subagent_type="frontend-developer"
74- Prompt: "Implement web version of feature using:
75  - React 18+ with Next.js 14+ App Router
76  - TypeScript for type safety
77  - TanStack Query for API integration: [API spec]
78  - Zustand/Redux Toolkit for state management
79  - Tailwind CSS with design system: [design specs]
80  - Progressive Web App capabilities
81  - SSR/SSG optimization where appropriate
82  - Web vitals optimization (LCP < 2.5s, FID < 100ms)
83  Follow shared business logic: [architecture doc]"
84- Context from previous: API contracts, design system, shared logic patterns
85- Expected output: Complete web implementation with tests
86 
87### 4b. iOS Implementation (SwiftUI)
88- Use Task tool with subagent_type="ios-developer"
89- Prompt: "Implement iOS version using:
90  - SwiftUI with iOS 17+ features
91  - Swift 5.9+ with async/await
92  - URLSession with Combine for API: [API spec]
93  - Core Data/SwiftData for persistence
94  - Design system compliance: [iOS HIG specs]
95  - Widget extensions if applicable
96  - Platform-specific features (Face ID, Haptics, Live Activities)
97  - Testable MVVM architecture
98  Follow shared patterns: [architecture doc]"
99- Context from previous: API contracts, iOS design guidelines, shared models
100- Expected output: Native iOS implementation with unit/UI tests
101 
102### 4c. Android Implementation (Kotlin/Compose)
103- Use Task tool with subagent_type="mobile-developer"
104- Prompt: "Implement Android version using:
105  - Jetpack Compose with Material 3
106  - Kotlin coroutines and Flow
107  - Retrofit/Ktor for API: [API spec]
108  - Room database for local storage
109  - Hilt for dependency injection
110  - Material You dynamic theming: [design specs]
111  - Platform features (biometric auth, widgets)
112  - Clean architecture with MVI pattern
113  Follow shared logic: [architecture doc]"
114- Context from previous: API contracts, Material Design specs, shared patterns
115- Expected output: Native Android implementation with tests
116 
117### 4d. Desktop Implementation (Optional - Electron/Tauri)
118- Use Task tool with subagent_type="frontend-mobile-development::frontend-developer"
119- Prompt: "Implement desktop version using Tauri 2.0 or Electron with:
120  - Shared web codebase where possible
121  - Native OS integration (system tray, notifications)
122  - File system access if needed
123  - Auto-updater functionality
124  - Code signing and notarization setup
125  - Keyboard shortcuts and menu bar
126  - Multi-window support if applicable
127  Reuse web components: [web implementation]"
128- Context from previous: Web implementation, desktop-specific requirements
129- Expected output: Desktop application with platform packages
130 
131## Phase 3: Integration and Validation
132 
133### 5. API Documentation and Testing
134- Use Task tool with subagent_type="documentation-generation::api-documenter"
135- Prompt: "Create comprehensive API documentation including:
136  - Interactive OpenAPI/Swagger documentation
137  - Platform-specific integration guides
138  - SDK examples for each platform
139  - Authentication flow diagrams
140  - Rate limiting and quota information
141  - Postman/Insomnia collections
142  - WebSocket connection examples
143  - Error handling best practices
144  - API versioning strategy
145  Test all endpoints with platform implementations."
146- Context from previous: Implemented platforms, API usage patterns
147- Expected output: Complete API documentation portal, test results
148 
149### 6. Cross-Platform Testing and Feature Parity
150- Use Task tool with subagent_type="unit-testing::test-automator"
151- Prompt: "Validate feature parity across all platforms:
152  - Functional testing matrix (features work identically)
153  - UI consistency verification (follows design system)
154  - Performance benchmarks per platform
155  - Accessibility testing (platform-specific tools)
156  - Network resilience testing (offline, slow connections)
157  - Data synchronization validation
158  - Platform-specific edge cases
159  - End-to-end user journey tests
160  Create test report with any platform discrepancies."
161- Context from previous: All platform implementations, API documentation
162- Expected output: Test report, parity matrix, performance metrics
163 
164### 7. Platform-Specific Optimizations
165- Use Task tool with subagent_type="application-performance::performance-engineer"
166- Prompt: "Optimize each platform implementation:
167  - Web: Bundle size, lazy loading, CDN setup, SEO
168  - iOS: App size, launch time, memory usage, battery
169  - Android: APK size, startup time, frame rate, battery
170  - Desktop: Binary size, resource usage, startup time
171  - API: Response time, caching, compression
172  Maintain feature parity while leveraging platform strengths.
173  Document optimization techniques and trade-offs."
174- Context from previous: Test results, performance metrics
175- Expected output: Optimized implementations, performance improvements
176 
177## Configuration Options
178 
179- **--platforms**: Specify target platforms (web,ios,android,desktop)
180- **--api-first**: Generate API before UI implementation (default: true)
181- **--shared-code**: Use Kotlin Multiplatform or similar (default: evaluate)
182- **--design-system**: Use existing or create new (default: create)
183- **--testing-strategy**: Unit, integration, e2e (default: all)
184 
185## Success Criteria
186 
187- API contract defined and validated before implementation
188- All platforms achieve feature parity with <5% variance
189- Performance metrics meet platform-specific standards
190- Accessibility standards met (WCAG 2.2 AA minimum)
191- Cross-platform testing shows consistent behavior
192- Documentation complete for all platforms
193- Code reuse >40% between platforms where applicable
194- User experience optimized for each platform's conventions
195 
196## Platform-Specific Considerations
197 
198**Web**: PWA capabilities, SEO optimization, browser compatibility
199**iOS**: App Store guidelines, TestFlight distribution, iOS-specific features
200**Android**: Play Store requirements, Android App Bundles, device fragmentation
201**Desktop**: Code signing, auto-updates, OS-specific installers
202 
203Initial feature specification: $ARGUMENTS
204