🐛 Key Challenges & Solutions

1. Document Hash Generation

Problem: Initially faced issues with consistent hash generation across different file sizes and types.

Solution:

• Implemented client-side file processing using

  ArrayBuffer

  and

  Uint8Array

• Used

  ethers.keccak256()

  for reliable hash generation
• Added error handling for large files

const convertFileToHash = async (file) => {
  try {
    const arrayBuffer = await file.arrayBuffer();
    const fileBytes = new Uint8Array(arrayBuffer);
    const hash = `0x${ethers.keccak256(fileBytes).slice(2)}`;
    return hash;
  } catch (error) {
    console.error("Error generating hash:", error);
    return null;
  }
};

2. Batch Verification Performance

Problem: Verifying multiple documents simultaneously caused UI freezes and poor performance.

Solution:

• Implemented batch processing with Promise.all()
• Added loading states and progress indicators
• Used React's useCallback for optimization

3. Smart Contract Integration

Problem: Race conditions when multiple users tried to register documents simultaneously.

Solution:

• Added mutex locks in smart contract
• Implemented proper error handling for "already registered" cases
• Added retry mechanism for failed transactions

4. Mobile Responsiveness

Problem: File upload UI broke on mobile devices and smaller screens.

Solution:

• Used Tailwind's responsive classes
• Implemented touch-friendly dropzone
• Added mobile-specific UI improvements

<div className="flex flex-col md:flex-row gap-4">
  {/* Responsive layout components */}
}

5. MetaMask Integration

Problem: Inconsistent wallet connections and network switching issues.

Solution:

• Used wagmi hooks for reliable wallet management
• Added network detection and auto-switching
• Implemented proper error messages for wallet states

These challenges helped improve both the codebase and user experience significantly.