The article discusses how the German soccer league Bundesliga enhanced its mobile app by introducing Bundesliga Shorts, a series of short-form vertical videos optimized for smartphone viewing. Amazon Personalize is used to provide personalized video recommendations for app users.

Specifically, the article covers:

• Bundesliga's motivation for embracing short-form vertical video content (Shorts) to engage new generations of fans.
• How user sign-up and account data is leveraged by Amazon Personalize to recommend relevant Shorts based on interests and past activity.
• The positive impact of Shorts and personalization on key performance indicators like app engagement, dwell time, and video consumption.
• Bundesliga's plans to further improve recommendation accuracy by incorporating additional context.