How excessive production logging can bury signal, increase cardinality, distort incident timelines, and make debugging slower even when every service appears well instrumented.
Why some bugs appear only under production load, how concurrency, data shape, queues, retries, and partial failures change behavior, and how to diagnose them without guessing.
Why production caches return stale or contradictory data, including cache-aside races, invalidation gaps, TTL drift, local cache divergence, write-through trade-offs, and safer rollout checks.