Duy Hai Doan, an Apache Cassandra Evangelist at DataStax, discusses the technical implementation of native secondary index in Cassandra and highlights best use-cases and worst anti-patterns. The article explains how secondary index is a distributed index that stores index data alongside original data on the same node to avoid issues with consistency levels and wide partitions. It also delves into the design schema for inverse index, read path optimization, and common anti-patterns to avoid when using native secondary index.