# Your App Will Fail, If You Don't Do This Source: https://www.youtube.com/watch?v=2DsDA2ly-Po Recap page: https://rapidrecap.app/video/2DsDA2ly-Po Generated: 2025-11-25T15:32:53.931+00:00 --- ## Quick Overview The critical step to prevent an application from failing when using AI code generation like Vibe Coding is to implement a strict refactoring plan that breaks down large files into smaller, manageable pieces, prioritizing high-impact changes like state management extraction first, and then rigorously testing each small change to avoid introducing errors that break the application. **Key Points:** - The developer identifies the main cause of app failure when using AI code generation (like Vibe Coding) as overly large files, specifically noting one file with 4,000 lines. - The proposed solution is to use Composer 1 (an agentic coding model) to create a refactoring plan, focusing first on extracting state management from the 860-line StudioEditorApp.tsx file into a new hook, useStudioState.ts. - The refactoring plan prioritizes high-impact changes first (like state management) and suggests a stepwise approach, aiming to reduce the main component size from 860 lines to under 100 lines. - The developer cautions against being too aggressive with refactoring, noting that attempting to reduce a 6,000-line file to 3,000 lines in one go caused the application to break. - The agentic tool successfully generated a plan that addresses the file size issue by breaking down the 860-line file into 7 focused hooks and components, confirming that structural improvements without behavioral changes are possible. - When testing the AI's execution of the plan, an error occurred because the AI referenced a file that didn't exist yet, highlighting the need to manually check or guide the execution flow when errors appear. ![Screenshot at 00:23: The speaker introduces the demonstration by showing the 'Thumbnails in seconds' landing page for the AI tool, setting the stage for a discussion on best practices for developing apps with AI.](https://ss.rapidrecap.app/screens/2DsDA2ly-Po/00-00-23.png) **Context:** The speaker, Corbin, is demonstrating how to manage large codebases while utilizing AI coding assistance, specifically focusing on how to refactor a massive component (StudioEditorApp.tsx, 860 lines) within a TypeScript/React project without breaking the application. He uses an AI agent tool, Composer 1, to analyze the code structure and suggest a detailed, phased refactoring plan to improve maintainability and reduce complexity, emphasizing the danger of aggressive, unchecked AI execution. ## Detailed Analysis Corbin discusses the critical need for a structured approach when using AI code generation tools like Vibe Coding to prevent application failure, especially when dealing with large files. He points out that letting the AI run unchecked on a large file (like one with 4,000 lines) can lead to immediate breakage. He then uses Composer 1 to analyze the largest file in his codebase, StudioEditorApp.tsx (860 lines), which coordinates many hooks and providers. The AI successfully generated a plan to break this file down into 7 focused hooks and components, reducing the main component to under 100 lines while preserving functionality. The plan prioritizes extracting state management first (high priority) and suggests using manual testing to verify changes. When the AI executed the plan, it initially failed because it referenced a file that hadn't been created yet, causing a reference error. Corbin notes that while the AI's plan is excellent, developers must still monitor the execution flow and manually intervene or correct errors, as the AI is not yet perfect at managing the step-by-step creation process. ### AI Refactoring Strategy - Identify 4,000-line files as a red flag - Start with the highest priority refactorings (e.g., state management) first - Prefer pure refactoring (no behavior changes) for safety - Use smaller increments instead of large restructuring efforts ### Composer 1 Analysis of StudioEditorApp.tsx (860 lines) - Identified 5 major areas for refactoring, including state management (860 lines), utility functions (827 lines), and prompt execution lifecycle (466 lines). - The main goal is to reduce the component to ~100 lines. ### Execution & Error Handling - The AI executed the plan, creating new hooks and refactoring files like useStudioState.ts and useStudioFeatures.ts. - An uncaught reference error occurred because the AI referenced a file that hadn't been created in an earlier step, demonstrating the need for manual oversight during execution. ### Model Comparison - The speaker briefly compares LLM choices (e.g., Sonnet 4.5 vs. Composer 1), recommending Composer 1 for coding tasks due to its optimized context window, though noting it can be slower than simpler models like Sonnet 4.5. ![Screenshot at 00:00: The presenter introduces the topic against the backdrop of the Thumio AI thumbnail generator website, promising tips for preventing app failure during AI development.](https://ss.rapidrecap.app/screens/2DsDA2ly-Po/00-00-00.png) ![Screenshot at 00:22: The presentation shifts to the development environment, showing the agent chat interface where the user asks the AI to find the top 5 files by line count in the repository.](https://ss.rapidrecap.app/screens/2DsDA2ly-Po/00-00-22.png) ![Screenshot at 01:00: The agent provides a detailed list of the top 5 largest files in the codebase, with StudioEditorApp.tsx being the largest at 860 lines, prompting the subsequent refactoring discussion.](https://ss.rapidrecap.app/screens/2DsDA2ly-Po/00-01-00.png) ![Screenshot at 02:43: The agent generates a detailed refactoring plan for StudioEditorApp.tsx, broken down into steps like extracting state management and hook orchestration.](https://ss.rapidrecap.app/screens/2DsDA2ly-Po/00-02-43.png) ![Screenshot at 10:34: After the AI executes the refactoring plan, the analysis panel shows that StudioEditorApp.tsx was successfully reduced from 860 lines to 485 lines, achieving significant structural improvement.](https://ss.rapidrecap.app/screens/2DsDA2ly-Po/00-10-34.png)