I already have some very well curated data in an existing ecommerce platform over at shopify. I intend to offer my inventory on both sites during the interim transition. To avoid overselling, it was essential that any changes in shopify products or inventory be replicated over to Winning Strategy Games.
Shopify has an admin rest API as well as support for third-party application's webhooks. I started by preparing a script that could access Shopify's REST API, download all my product data, and inject it into my WSG platform. Success! We have products.
However, having shopify push on change is far more efficient than pulling periodically. I added a REST endpoint over at WSG to accept updates to product data. Success again! As an added bonus, Shopify polls with updated inventory every time an order is processed through any of the sales channels (inventory is already listed at Ebay and Shopify). Everyone is synced up to avoid any over-selling incidents.