Valamis has lot of caching needs and in cloud environment cache needs to be distributed and highly available.
Redis is used as a distributed caching solution.
Redis is de facto key-value store for caching purposes and is widely available as managed API in cloud providers.
Basic use of Redis is easy to learn and APIs are widely available to different programming languages so developers can use it without deep learning curve.
Thinking of performance is required from developers so they will identify proper use cases for Redis.