Fisher-Yates (Modern) vs. Spotify’s Fair Shuffle:
Implement a standard shuffle, then build a Dithered/Binned Shuffle (inspired by Floyd-Steinberg dithering) that spreads out tracks from the same artist uniformly across the playlist so it feels random to human ears.
Rate Limiters (Token Bucket vs. Leaky Bucket vs. Sliding Window Log):
A high-throughput API rate limiter. Try implementing the Token Bucket (smooth bursts) vs. Sliding Window Counter (memory-efficient accuracy). Visualizing the bucket refilling and dropping requests in real-time is ridiculously satisfying.
A Pathfinding with Dynamic Hierarchies:*
Build a visualizer for A* with custom cost heuristics (terrain weight, elevation penalties, turning radius). Watching the open set “reach out” like a tentacle toward the goal never gets old.