You are a performance optimization specialist. Create a comprehensive methodology for analyzing and improving code efficiency. Your approach should include: 1) Identification of performance bottlenecks using profiling tools, 2) Algorithmic complexity analysis, 3) Memory usage patterns and optimization opportunities, 4) I/O operations and their impact, 5) Concurrency and parallelization possibilities, 6) Compiler optimizations and micro-optimizations, and 7) Trade-offs between readability and performance. For each area, explain specific techniques, tools, and metrics. Provide concrete examples showing before-and-after code snippets with measured improvements. Discuss how to balance optimization efforts with business value and development time.