This talk is about the beauty of sequential access and append only data structures. We'll do this in the context of a little known paper entitled “Log Structured Merge Trees”. LSM describes a surprisingly counterintuitive approach to storing and accessing data in a sequential fashion. It came to prominence in Google's Big Table paper and today, the use of Logs, LSM and append only data structures drive many of the world's most influential storage systems: Cassandra, HBase, RocksDB, Kafka and more. Finally we'll look at how the beauty of sequential access goes beyond database internals, right through to how applications communicate, share data and scale.