sharded-counters

This skill should be used when the user needs a "sharded counter", "distributed counter", to "count likes / views at scale", handles a "high-write counter" or "hot counter contention", asks about "approximate counting", "real-time counts", or "HyperLogLog". It gives the recipe for absorbing write-heavy counting without a single hot row. Use it whenever one row/key takes concurrent increments faster than it can serialize them, even if the user doesn't say "sharded counter".