BUILDING A RESILIENT DATA PLATFORM WITH WRITE-AHEAD LOG AT NETFLIX

Summary from the TLDR Web Dev newsletter

Netflix built a Write-Ahead Log (WAL) system for data consistency, reliability, and efficient operations across its massive infrastructure. The WAL system has a simple API, allowing it to function as a delayed queue, enabling generic cross-region replication for services like EVCache and handling multi-partition mutations in Key-Value stores. By writing to the WAL first, applications gain eventual consistency, systematic replication, and automatic retries.