I need a complete, from-scratch build that covers three tightly-linked pieces of work: 1. A small web portal where merchants can sign up, log in and recharge a prepaid wallet. The balance will be held on our side and exposed through a simple REST/JSON API. 2. A WooCommerce plugin and a Shopify app developed in parallel. Each must: • Call the wallet API on every successful order, deduct a fixed per-sale fee and record the transaction ID. • Check balance before charging; if funds are exhausted, automatically disable itself so no further orders can be completed until the merchant tops up. • Offer the merchant a quick link back to the portal’s recharge page. 3. Settlement logic in the portal that lets me see charges, balances and manual adjustments at a glance. The site can be a lightweight Laravel, Node or Django build—whatever you are fastest with—as long as the API is clean and well-documented for future use. Security, webhook verification and graceful error handling are non-negotiable. Please tell me about your experience building BOTH WooCommerce extensions and Shopify apps that connect to third-party payment or wallet services; links to live installs or code samples will win extra points. I’ll shortlist based purely on that experience, then share the precise API spec and fee structure so you can give a final estimate and schedule.