Environment variables should be properly validated with correct type checking and without redundant conditions. Common issues include comparing strings to integers and using unnecessary double-checks that can lead to unexpected behavior. **Key principles:** 1. **Avoid redundant checks**: Don't check if an environment variable exists and then check its value in the same condition 2. **Use correct types**: Environment variables are always strings, so compare against string values 3. **Simplify boolean logic**: Use direct comparisons instead of complex conditional chains **Examples of issues and fixes:** ❌ **Problematic patterns:** ```ruby # Redundant checking if ENV["RCT_USE_PREBUILT_RNCORE"] && ENV["RCT_USE_PREBUILT_RNCORE"] == "1" # Type mismatch - comparing string to integer return ENV["RCT_NEW_ARCH_ENABLED"] == 0 ? false : true ``` ✅ **Improved patterns:** ```ruby # Direct value check if ENV["RCT_USE_PREBUILT_RNCORE"] == "1" # Correct string comparison with simplified logic return ENV["RCT_NEW_ARCH_ENABLED"] != "0" ``` This approach prevents runtime errors, improves code readability, and ensures consistent behavior across different environments and deployment scenarios.