Ecommerce have evolved over the last 2 decades and has become quite complex and expensive to build from scratch primarily due to the need to compete with Amazon and the drive to create a feature rich system as well as an exceptional user experience. I should add that my response is based solely on my experience with Magento eCommerce Platform, which does allow the feature you are describing ie- presenting trending items to your website visitors.
I’m assuming you mean “Items promotion”. In other words, you are selecting certain items to feature or promote on the website.
Magento used to be an open source ecommerce platform until it was acquired by Adobe and the business model changed. Magento does support “Promotions” or “trending items” to be built into your ecommerce website. So I’m assuming that competitive platforms like Moltin also offer support for “promotions” or “trending items”.
I’m also assuming that “trending items” are derived from SEO on your website, conversations with other channels, and from analyzing your competitor’s websites. What I need to understand is if the discovery of trending items is automated or if that data has to be manually transferred from respective data/analytic sources to your ecommerce engine and then on to your ecommerce site.
One thing to keep in mind with APIs (application programming interface) is that you can build whatever features you want and connect it the application.
Here’s what I found out from Moltin-
Catalog Control -
Figure 2: Flexible and scalable allows new features to be added to the platform
Figure 3: Modify the catalog category to suit your business objectives