Write a Bash performance optimization guide in a {{tone}} tone for {{target_audience}}. Focus on {{focus_area}} with goal {{performance_goal}}. Include: Step 1 (measure current performance with metrics and profiling tools), Step 2 (identify bottlenecks using profiler output and analysis), Step 3 (10 optimization techniques ordered by impact with implementation and trade-offs), Step 4 (validate improvements via A/B testing and monitoring). Add Bash-specific performance tips and a performance budget section. Use precise technical terminology, include code examples, and document assumptions. Keep under 1800 words. Skip any section if information is unknown. Paste any relevant background information after these instructions before running.