# Project Guidelines

## Language & Framework
- Kotlin with Spring Boot 3.x
- Gradle with Kotlin DSL
- JDK 21 with virtual threads

## Architecture
- Hexagonal architecture (ports & adapters)
- Domain events for cross-module communication
- CQRS for read-heavy endpoints

## Code Standards
- Follow Kotlin coding conventions
- Use data classes for DTOs
- Prefer sealed classes for domain errors
- Extension functions over utility classes

## Testing
- JUnit 5 with Kotest assertions
- Testcontainers for integration tests
- MockK for mocking (not Mockito)

## Build & Run
- Build: ./gradlew build
- Test: ./gradlew test
- Run: ./gradlew bootRun

# Application Guidelines

## Architecture
- This is a monorepo managed with Turborepo
- Apps: web (Next.js), api (Express), mobile (React Native)
- Shared packages: ui, config, types

## Code Standards
- TypeScript strict mode in all packages
- Use barrel exports (index.ts) for public APIs
- No default exports; use named exports everywhere
- Prefer async/await over raw Promises

## API Design
- RESTful endpoints follow /api/v1/{resource} pattern
- All responses use { data, error, meta } envelope
- Validate request bodies with Zod schemas
- Return 4xx for client errors, 5xx for server errors

## Database
- Use Prisma ORM for all database operations
- Migrations checked into source control
- Soft-delete pattern: use deletedAt timestamp, never hard delete
- All timestamps stored as UTC

## Testing
- Jest for unit tests, Playwright for E2E
- Test files colocated: foo.ts -> foo.test.ts
- Mock external services, never call real APIs in tests