Redis is a popular key-value store, commonly used as a cache or message broker service. However, it can do so much more than just hold string values in memory! -- Redis is a full featured “data structure server”. As PHP developers, we typically don’t think about data structures other than our jack-of-all-trades array, but Redis can store hashes, lists, sets, and sorted sets, in addition to operating on string values. In this talk, we’ll explore these basic data structures in Redis and look at how we can apply them to solve problems like rate limiting, creating distributed locks, or efficiently checking membership in a massive set of data.