Status: IN
Both consistent hashing and leaderboard implementations maintain parallel data structures (three in consistent hashing, two in leaderboard) that must stay synchronized on every mutation. In consistent hashing, all three structures must stay consistent on every add/remove; in leaderboard, a desync between the sorted list and dict is a correctness bug that surfaces as a ValueError on the next operation.
Multi-structure sync is a recurring correctness burden where the failure mode is silent divergence
Depends on (SL): ch-triple-bookkeeping, leaderboard-dual-index-consistency