# Project Conventions

## Language
- TypeScript strict mode, no `any` types
- Prefer const over let, never use var
- Use template literals over string concatenation

## Architecture
- Feature-based folder structure under src/features/
- Each feature exports through an index.ts barrel file
- Shared utilities go in src/lib/

## Error Handling
- Use Result<T, E> pattern for expected failures
- Throw only for programmer errors
- Always log errors with structured context

## Testing
- Colocate tests next to source files (*.test.ts)
- Use factories for test data, not fixtures
- Integration tests in __tests__/ directories

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# Project Standards

## Stack
- TypeScript 5.x with Node.js 22
- AWS CDK v2 for infrastructure
- DynamoDB for data, S3 for assets

## Conventions
- Use ESM imports, not CommonJS
- Lambda handlers export a named `handler` function
- Use middy middleware for cross-cutting concerns
- All API responses follow JSON:API format

## Testing
- Unit tests with vitest
- Integration tests with aws-testing-library
- E2E tests use deployed staging environment