Validate performance impact first

Always validate performance changes through profiling or benchmarking before implementation, and favor memory-efficient patterns when making optimizations. Key practices:

1. Profile before/after significant changes:

   // Before changing buffer sizes, validate impact:
   const SCROLLBACK_LEN: usize = 1024;
   // Profile current performance
   // Test new value
   const SCROLLBACK_LEN: usize = 2048;
   // Validate no significant regression
   

2. Use memory-efficient patterns:
   • Prefer &str over &String to avoid double indirection
   • Initialize collections with capacity when size is known:

     let mut map = HashMap::with_capacity(items.len());
     

   • Return iterators instead of collecting vectors when possible:

     // Instead of
     pub fn get_items(&self) -> Vec<String> {
      self.items.iter().map(|i| i.to_string()).collect()
     }
     // Prefer
     pub fn get_items(&self) -> impl Iterator<Item = &str> + '_ {
      self.items.iter().map(|i| i.as_str())
     }
     

3. Document performance-critical decisions with benchmarks or profiling results to justify changes.