Zalando API

Basically integrate our SHOPIFY website with Zalando

See below guidelines from Zalando of the project:

Zalando Partners use the zDirect API to integrate with the Merchant Platform. The zDirect API is a RESTful API that covers all stages of partner integration. You may use it to submit your products to the Zalando system, set prices and available stock, fulfill orders, track shipments to and from Zalando warehouses, and more.

Integration Overview
All Merchant Platform partners go through two stages of zDirect integration:
Initial integration: During this stage, partners prepare to sell their products by submitting them to the Zalando system, validating their submissions for accuracy and completeness, and setting prices and available stock for products.
Live Business Management: After Go Live, partners actively sell and manage their products in the Merchant Platform. When customers place orders through Zalando Fashion Stores, partners either fulfill those orders themselves (Partner Fulfillment), or Zalando fulfills orders on their behalf (Zalando Fulfillment Solutions). During this stage, many implementation details depend on which fulfillment model you are using.
For more information on the stages of integration and an overview of which APIs are used at each stage, see Stages of Integration.
Integration occurs in two main stages:

Initial Integration: Initial setup and product onboarding, preparation for Go Live.
Live Business Management: Order fulfillment and stock management.
Initial Integration
During Initial Integration, partners submit all of the required product information and assets that Zalando needs to list your products on our Fashion Stores. Once products have been entered, partners set prices and available stock, and when everything is complete, your offerings will go live.
Product Onboarding
Partners begin by using the Products API to search for each product's EAN to see if they already exist in the Zalando Catalog. If so, you may simply map your product to the existing entry.

For each product that does not yet exist in the Catalog, use the Product Attributes API to find out what information Zalando requires for each type of product. Then use the Product Submissions API to submit the required data as a JSON file for each product.
Repeat this process for all products.
Validation
Zalando works with partners in a three-step validation process to verify that all product submissions are accurate and compete.
Once a product is submitted, you may use your Product Status Report (PSR) in zDirect to check the status of the submitted product at any time. If we find any issues or need more information, it will be reported through the PSR. When you have made any necessary changes, use the Product Submissions API to re-submit your entry.

Setting Prices and Stock
Once a product is created on the Zalando system, use the Prices API to set the price of each product for each sales channel through which it is sold, and use the Offers API to set available stock.

Note that once a product is successfully created, you may set stock and price for it at any time, even if other product submissions are still being verified.

There are additional business steps that must be completed before Go Live. For more information, see Zalando Partner University.

Live Business Management
During the Live Business Management stage, use the Offers and Prices APIs to make any necessary changes to stock and prices. Use the Orders API to manage orders, and track shipping with the Stock Movements API.
Partner Fulfillment and Zalando Fulfillment Solutions (ZFS)
The zDirect API is used for order fulfillment when customers place orders through Zalando Fashion Stores. The details of how orders are fulfilled depend on whether you are fulfilling the orders yourselves, or using Zalando Fulfillment Solutions:
Partner Fulfillment: You are responsible for fulfilling orders placed through a Zalando Fashion Center.
Zalando Fulfillment Solutions: Zalando is responsible for order fulfillment and takes over the entire customer-facing logistics chain, including packaging and delivery. Partners are responsible for monitoring inventory and shipping stock to Zalando Warehouses for fulfillment.
Order Fulfillment with Partner Fulfillment
Partners use the Orders API to get and update customer order information. The diagram below illustrates the basic steps of order fulfillment: