Redis Mastery (Senior → Principal) Operate - Confirm whether Redis is a cache, primary store for ephemeral state, coordination primitive, queue, or all of the above. - Treat memory, eviction, persistence, and hot key behavior as core architecture decisions. - Prefer simple data lifecycles with explicit TTL and ownership. - Design for cache invalidation and degraded-mode behavior up front. Default Standards - Every cache needs a miss strategy and staleness policy. - Hot keys, large values, and unbounded cardinality are production risks. - Pick persistence mode based on recovery objectives, not…