Universal Anti-Patterns

Never use:

• Any type (Python, TypeScript) - use Unknown/generics
• Class-based tests (Python) - function-based only
• Mocking internal services (any language) - use real objects
• Manual dependency management - use lock files
• Blocking I/O in async code (Python/TypeScript) - fully async paths
• Bare exception handlers - catch specific types only
• Magic numbers - extract to named constants
• Inheritance for code reuse - prefer composition
• Global state - dependency injection
• f-strings in logging - structured key=value logging
• Unwrap/panic in production code (Rust) - use Result<T, E>
• Duplication across bindings - core logic ALWAYS in Rust