Your "Cache Invalidation is Hard" Answer Misses the Real Horror

The article pushes back on the cliché that cache invalidation is just a hard interview question, showing it can break real production workflows.

In distributed systems, stale cache entries can corrupt critical actions like payments, inventory updates, account balances, and customer operations.

The piece recommends active, event-driven invalidation after database writes instead of relying only on TTLs or passive expiry.

It highlights how tools like Redis, Kafka, and Postgres are often part of the consistency strategy for high-stakes systems.