Inefficient Algorithm Causing Request Timeouts

1. Nested loops creating O(n²) or O(n³) complexity (sorted list checking for each item)
2. Inefficient search: linear search where binary search should be used
3. Unnecessary array copying in loop creating O(n²) memory usage
4. Recursive algorithm without memoization, recalculating same values
5. Sorting inside loops instead of once before loop

Profile the slow endpoint with realistic dataset size. Look for nested loops and recursive calls. Use appropriate data structures: HashSet for O(1) lookup, sorted array for binary search. Avoid creating new objects in tight loops. Memoize/cache expensive calculations. Consider pagination: process in batches instead of all at once.