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 Implementation (Kotlin/Compose)

Use Task tool with subagent_type="mobile-developer"

Prompt: "Implement Android version using:

Jetpack Compose with Material 3

Kotlin coroutines and Flow

Retrofit/Ktor for API: [API spec]

Room database for local storage

Hilt for dependency injection

Material You dynamic theming: [design specs]

Platform features (biometric auth, widgets)

Clean architecture with MVI pattern

Follow shared logic: [architecture doc]"

Context from previous: API contracts, Material Design specs, shared patterns

Expected output: Native Android implementation with tests

4d. Desktop Implementation (Optional - Electron/Tauri)

Use Task tool with subagent_type="frontend-mobile-development::frontend-developer"

Prompt: "Implement desktop version using Tauri 2.0 or Electron with:

Shared web codebase where possible

Native OS integration (system tray, notifications)

File system access if needed

Auto-updater functionality

Code signing and notarization setup

Keyboard shortcuts and menu bar

Multi-window support if applicable

Reuse web components: [web implementation]"

Context from previous: Web implementation, desktop-specific requirements

Expected output: Desktop application with platform packages

Phase 3: Integration and Validation

5. API Documentation and Testing

Use Task tool with subagent_type="documentation-generation::api-documenter"

Prompt: "Create comprehensive API documentation including:

Interactive OpenAPI/Swagger documentation

Platform-specific integration guides

SDK examples for each platform

Authentication flow diagrams

Rate limiting and quota information

Postman/Insomnia collections

WebSocket connection examples

Error handling best practices

API versioning strategy

Test all endpoints with platform implementations."

Context from previous: Implemented platforms, API usage patterns

Expected output: Complete API documentation portal, test results

6. Cross-Platform Testing and Feature Parity

Use Task tool with subagent_type="unit-testing::test-automator"

Prompt: "Validate feature parity across all platforms:

Functional testing matrix (features work identically)

UI consistency verification (follows design system)

Performance benchmarks per platform

Accessibility testing (platform-specific tools)

Network resilience testing (offline, slow connections)

Data synchronization validation

Platform-specific edge cases

End-to-end user journey tests

Create test report with any platform discrepancies."

Context from previous: All platform implementations, API documentation

Expected output: Test report, parity matrix, performance metrics

7. Platform-Specific Optimizations

Use Task tool with subagent_type="application-performance::performance-engineer"

Prompt: "Optimize each platform implementation:

Web: Bundle size, lazy loading, CDN setup, SEO

iOS: App size, launch time, memory usage, battery

Android: APK size, startup time, frame rate, battery

Desktop: Binary size, resource usage, startup time

API: Response time, caching, compression

Maintain feature parity while leveraging platform strengths.

Document optimization techniques and trade-offs."

Context from previous: Test results, performance metrics

Expected output: Optimized implementations, performance improvements

Configuration Options

--platforms

Specify target platforms (web,ios,android,desktop)

--api-first

Generate API before UI implementation (default: true)

--shared-code

Use Kotlin Multiplatform or similar (default: evaluate)

--design-system

Use existing or create new (default: create)

--testing-strategy

Unit, integration, e2e (default: all)

Success Criteria

API contract defined and validated before implementation

All platforms achieve feature parity with <5% variance

Performance metrics meet platform-specific standards

Accessibility standards met (WCAG 2.2 AA minimum)

Cross-platform testing shows consistent behavior

Documentation complete for all platforms

Code reuse >40% between platforms where applicable

User experience optimized for each platform's conventions

Platform-Specific Considerations

Web

PWA capabilities, SEO optimization, browser compatibility

iOS

App Store guidelines, TestFlight distribution, iOS-specific features

Android

Play Store requirements, Android App Bundles, device fragmentation

Desktop

Code signing, auto-updates, OS-specific installers Initial feature specification: $ARGUMENTS