# Kotlin Conventions

## Language Features
- Use Kotlin 2.x with coroutines for async work
- Prefer data classes for DTOs and value objects
- Use sealed classes/interfaces for domain errors
- Extension functions over utility classes

## Spring Boot
- Constructor injection (no field injection)
- Use @ConfigurationProperties over @Value
- Prefer WebFlux for reactive endpoints
- Use Spring Security with method-level security

## Testing
- JUnit 5 with Kotest assertions
- MockK for mocking (not Mockito)
- Testcontainers for integration tests
- Use @Nested for test organization

# Project Rules

## Stack
- TypeScript 5.x with strict mode
- React 19 + Next.js 15 (App Router)
- Tailwind CSS v4 for styling
- Drizzle ORM for database access

## Code Standards
- Named exports only (no default exports)
- Prefer `const` assertions and satisfies operator
- Use Result<T, E> pattern for error handling
- Maximum 30 lines per function

## File Organization
- Colocate tests: `foo.ts` → `foo.test.ts`
- One component per file
- Barrel exports (index.ts) for public module APIs

## Git
- Conventional commits: feat|fix|chore|docs|test
- Squash merge feature branches
- Branch naming: type/description