Using an MCP Server to Optimize React Native Apps with Claude Code

An MCP server has been configured to stream live runtime data from a running React Native app directly into Claude Code, which is an AI tool for identifying and resolving code issues. This setup allows developers to pinpoint bottlenecks and inefficiencies based on real-time data.

Key Details

• The MCP server captures runtime data such as renders, state changes, and network requests.
• Using this data, Claude Code identified 10,000 unnecessary renders in just 12 seconds.
• The tool also detected 73 state updates in 12 seconds from the Zustand store, indicating thrashing due to every post subscribing to the entire store. This was resolved with a one-line fix.
• Another issue involved each post mounting a hidden BottomSheetModal for a menu, unnecessarily multiplying re-render costs.
• Claude traced causal chains from store updates through to re-render cascades, providing exact lines of code for potential fixes.
• Identified 126 reference-only prop changes across multiple files, which defeated memoization benefits.

This setup is particularly beneficial for developers looking to optimize the performance of their React Native applications by addressing underlying issues that may not be visible through standard crash reports or user feedback.