# Multiregion

As we scale Sentry, we need to expand Postgres capacity by splitting up workloads across multiple primaries.

Cross-region replication is a foundational subsystem in multi-region Sentry. This post explores our design process.

Before splitting our application database and infrastructure up, we wanted to have confidence in where the boundaries would be.

Almost 2 years ago, Sentry embarked on a project to bring true EU data residency to Sentry's customers. We decided to do it the hard way.