Ask HN: Practical applications of algorithms and data structures

It's easy to find information about algorithms and data structures. But where can I find books or articles about the practical applications of algorithms and data structures to solve a real-world problem? For example:

- Building secondary indexes on ordered sets (with Redis, but valid for any implementation of ordered sets): https://redis.io/topics/indexes

- Building a graph database (hexastore) on top of a ordered key value store: http://nodejsconfit.levelgraph.io/

- key-value store using the append log data structure: https://www.poeticoding.com/build-a-simple-persistent-key-value-store-in-elixir-using-logs-part-1/