refactor-performance

name	refactor-performance
description	Analyze and refactor selected code to improve performance.

Description

This skill inspects the selected code for performance bottlenecks and proposes a refactored version that is more efficient and scalable.

When to use

• A function or component feels slow or heavy.
• You see repeated computations or large loops.
• You suspect N+1 database queries or unnecessary re-renders.

Instructions

1. Analyze the selected code for:
   • Unnecessary re-renders (React components).
   • N+1 query patterns or inefficient database access.
   • Heavy synchronous computations on the main thread.
   • Memory leaks or unnecessary object retention.
2. Explain the main performance issues found.
3. Propose a refactored version of the code that:
   • Reduces time complexity where possible.
   • Minimizes redundant computations or network calls.
   • Uses appropriate memoization, batching, or pagination techniques.
4. Clearly state:
   • Before vs after complexity (e.g. O(n²) to O(n)).
   • Any trade-offs introduced by the refactor.
5. Ensure the refactored code stays readable and maintainable.

Examples

Example input (user intent)

Refactor this list rendering logic; it feels slow on large datasets.

Example output (high level)

• Explanation of why the current implementation is slow.
• Refactored React component using virtualization or memoization.
• Note on expected performance improvement.