Shuffle: Making Random Feel More Human

Key takeaways

• Spotify addresses the 'clustering' problem where true randomness leads to repetitive sequences of artists or genres.
• The engineering team transitioned from standard Fisher-Yates shuffling to a 'balanced shuffle' algorithm.
• The balanced approach is inspired by dithering techniques used in image processing to distribute points evenly.
• The algorithm calculates ideal distances between tracks from the same artist to prevent back-to-back occurrences.
• This method improves user satisfaction by aligning the shuffle logic with human psychological expectations of variety.