There isn't one single magic tool for this. Instead, you have to choose between two main strategies for managing your listings across Amazon and Walmart. The choice really depends on the complexity of your product catalog.
For brands with a large or frequently-changing catalog, the hosts I listened to often point to a Product Information Management (PIM) system. On the 2X eCommerce Podcast, Kunle Campbell repeatedly brings up Salsify as a great example. A PIM acts as a central source of truth for product information, ensuring all your descriptions, specs, and images are consistent when you publish them to different channels. As Darin Lynch mentioned on the Up Arrow Podcast, without a strong feed management system, you risk having mismatched or incomplete data on crucial marketplaces like Amazon.
For a more streamlined, workflow-based approach, you can use Shopify as your hub. Bert Leffel explained on Ecommerce Coffee Break how his business uses software to pull product data into Shopify, then uses the Shopify’s Marketplace Connect feature to push those listings out to Amazon, Walmart, and eBay. This is a powerful method for keeping your listings and inventory in sync from one central dashboard without needing a more enterprise-level PIM.
Your first move is to decide which philosophy fits your business. Are you managing a complex catalog that needs a PIM, or can you run your multi-channel selling operation efficiently through a Shopify-centric workflow?