Learn why platforms struggle with new users who have no history, and how they solve it
Educational content slides
You download TikTok. Open it. First hour feels chaotic:
Cooking video (watch 2 seconds, skip)
Prank video (watch 3 seconds, skip)
Anime edit (watch 47 seconds, like, comment)
Dance video (watch 8 seconds, skip)
Anime meme (watch full video, share)
Within 20 minutes: TikTok knows you better than Instagram after 2 years
The secret: Aggressive exploration with rapid feedback. Each skip/watch/like is a data point. Short videos = fast learning.
This solves the cold start problem in real-time.
Why does Spotify ask new users to pick 3 favorite artists during signup?
Complete this exercise and get AI-powered feedback.
Cold start is every recommendation system's first challenge. How you solve it determines whether users stay or leave.
Think about: How to gather data quickly without annoying users, when to explore vs exploit, how to balance learning and satisfaction.
This reveals: The fundamental tension between learning and serving in recommendation systems.