Building a multi-region Rails application with PlanetScale

This post details how to build a multi-region Rails application by co-locating database replicas with application servers globally. It covers setting up read-only replicas in different regions, configuring Rails' Active Record to use multiple databases (primary for writes, replicas for reads), and addressing replication lag with a 2-second delay for reading own writes. The post also explains how to dynamically connect to the nearest database replica based on application deployment region, significantly reducing latency for read-heavy workloads.