AliExpress, one of the world's biggest online retailers, provides an API to developers so they can integrate it into their own applications. The AliExpress API offers various endpoints for searching products, browsing categories, product details, and shipping information. Using this API with Ruby, developers can build a simple app that allows users to navigate the API easily. The app includes features such as displaying categories, products, and search functionality, with the ability to add links to individual products and display product details, including shipping options and seller descriptions. With the AliExpress API, developers can tap into vast amounts of data from one of the world's largest online retailers.