This document discusses 9 use cases for Redis in applications: 1) Real-time analytics like tracking KPIs and leaderboards, 2) Storing session/API tokens with expiration, 3) Offloading background jobs to task queues, 4) Eliminating duplicates within time windows, 5) Rate limiting requests, 6) IP blacklisting, 7) Storing feature flags, 8) Enabling real-time notifications via pub/sub, and 9) Building autocomplete APIs using sorted sets. Redis offers scalability, performance, and reliability benefits for these common use cases.