The problem ZapCrow solves

The Problem

International trade is broken. Buyers won't pay before receiving goods. Sellers won't ship before getting paid. Traditional escrow solutions are slow (weeks), expensive (2-5% fees), and require complex paperwork.

Our Solution

ZapCrow uses Lisk blockchain smart contracts to create instant, automated escrow that:
⚡ Fast - Minutes, not weeks💰 Cheap - 0.5-1% fees (80% cheaper)🌍 Global - Works anywhere, no bank required🔒 Trustless - Code enforces
the deal, not people📄 Compliant - Built-in docs & tax calculation

How It Works

1. Buyer deposits funds into smart contract
2. Seller ships goods & uploads proof
3. Buyer confirms receipt
4. Funds auto-release to seller

Perfect For:

• Manufacturers selling to overseas retailers
• Freelancers working with international clients
• Importers/Exporters needing secure payments
• Any business tired of expensive, slow traditional escrow

Challenges I ran into

During user testing, we discovered a critical race condition in our escrow funding flow. Users who clicked the "Fund Escrow" button multiple times during the approval phase would accidentally initiate duplicate blockchain transactions, potentially losing funds to unnecessary gas fees and creating multiple conflicting transactions.
The bug occurred because our two-step process (approve → fund) had a brief window where the button re-enabled between transactions:

• User clicks "Fund Escrow" → Approval starts
• Approval completes → Button briefly enables
• Auto-funding starts → User clicks again → Duplicate transaction!
  We managed to fix this using a comprehensive state management.