Hey, Original blog post author here.

What a lot of people don't understand is that you want it both. The resilience of Postgres and the speed of fetching from Redis.

You have data stored. You want to retrieve it as painlessly (shorter time, less CPU usage, less complexity, etc.) as possible. What are the options? How much faster is Redis? How much RAM is that going to eat up? Different tools have different properties. Run some tests to answer some of those questions. Don't just guess. Sure Redis is going to save some time, but how much? Do you know by heart?