Zero to Multi-Region: High Availability Serverless with Cloud Run and Cross-Region Failover & Failback

Google just made multi-region Cloud Run significantly easier. Here is the full picture; what changed, what it means in practice, and how to build it right. Most teams discover they need multi-region architecture the hard way and sadly, during an outage. Whether you're running a global e-commerce platform, a real-time gaming API, or a financial services application, users expect your service to be available whenever they need it. There is a conversation that happens in almost every engineering team at some point. It usually starts with a post-mortem. A regional Google Cloud outage or a Cloud Run service that hit a cold start spike, or a single-region deployment that could not handle the latency demands of users spread across Lagos, Nairobi, and London simultaneously, caused enough pain that someone finally asked: why are we only deployed in one region? The answer is usually one of three things: it felt complex, it felt expensive, or no one had prioritised it yet. In July 2026, Google moved Cloud Run Service Health to General Availability and the timing was hard to miss. Six days earlier, a power cut at Google's Netherlands data centre had knocked three services offline. The GA release brings automatic cross-region failover to Cloud Run with what Google describes as a two-step setup: add a readiness probe, set minimum instances to at least 1. The load balancer does the rest. This article covers the full architecture, what Service Health is, how readiness probes underpin it, how to set up the Global Load Balancer correctly, and how to test that failover actually works. It also covers the production details. What changed: Service Health and readiness probes Before Service Health, multi-region Cloud Run required you to implement a /health endpoint in your application and configure a separate HTTPS health check at the load balancer level. This worked, but it had a significant gap. The load balancer's health check only knew whether the Cloud Run service endpoint was respon