Testcontainers Best Practices for .NET Integration Testing

Testcontainers enables reliable .NET integration testing by spinning up real Docker containers for dependencies like PostgreSQL and Redis. Key practices include using IAsyncLifetime for container lifecycle management, implementing proper xUnit fixtures (class vs collection) based on test isolation needs, and configuring dynamic connection strings through WebApplicationFactory. The approach eliminates test pollution and provides production-like testing environments while maintaining clean separation between infrastructure setup and business logic testing.