You can choose whichever challenge you like, so be sure to choose the one that you feel will make you shine!
In this challenge, demonstrate how you would build a web application against a high-volume API.
In this challenge, demonstrate what it means to build a Single Page Application while still maintaining perfect SEO for a complex app used by a huge number of users.
In this challenge, demonstrate your approach to testing frontend UI and how you ensure it doesn't become a pain while making your fellow designer happy.