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When you're designing for the cloud, or more importantly across clouds, you have to think beyond uptime — because things fail, regions go down, data gets corrupted. The question isn't if it will happen, but how quickly you can recover when it does.

That's where backup and disaster recovery come into play.

Now, a lot of times backups and disaster recovery get lumped together, but they're actually serving different purposes. A backup is a copy of your data taken at a point in time, so you can restore it later if it's lost, deleted, or corrupted. Disaster recovery, on the other hand, is about keeping your business running even when an entire data center, or region, or even provider becomes unavailable.

So let's talk about backups.

In AWS, you have services like AWS Backup and Amazon S3 Versioning, which automate snapshots and retention across multiple services. Azure offers a similar experience through Azure Backup and Recovery Services Vaults. Both clouds let you store backups in separate regions, encrypt them, and automate retention policies so you don't have to manage old copies manually.

The main idea is that backups are your safety net. While they aren't designed for instant failover, they do protect against accidental deletion, things like ransomware, and corruption.

When you're operating across AWS and Azure, you might even choose to back up data from one cloud to the other. For example, you could backup your AWS S3 data to Azure Blob storage as a secondary copy, giving you an extra layer of resilience in case of a major provider outage.

That brings us to disaster recovery, which is all about continuity. In a multicloud design, DR is where you start to see the real payoff of using more than one cloud. Maybe your primary workloads live in AWS, but you replicate your databases or virtual machines into Azure, so that if AWS goes down you can fail over and keep running.

The trick is to decide what level of recovery you actually need.

That's defined by two terms: recovery point objective, or RPO, and recovery time objective, or RTO. RPO is how much data you can afford to lose, measured in time. For instance, an RPO of one hour means you can tolerate losing up to an hour's worth of data. RTO is how long it takes to get everything up and running again. An RTO of five minutes means you need near-instant failover. These two numbers drive everything about DR design: how you replicate, where you replicate, and how much it costs.

If your RTO and RPO are both tight, you'll likely use real-time replication. For example, AWS Elastic Disaster Recovery can continuously replicate EC2 instances into a secondary region, or even into Azure if you're building a cross-cloud solution. Azure Site Recovery does the same thing for Azure VMS or on-prem servers, keeping them ready to start up in another region if something goes wrong.

If you have a higher tolerance for downtime, you might go with a cold standby approach instead. That means your backup data sits idle until you need it. It's cheaper because you're not paying for live compute, but recovery takes longer because you'll need to deploy or restore everything from storage before you can come back online.

When you're working across different clouds, cost and complexity become major considerations, because you can't just mirror everything one-to-one between AWS and Azure. If you did this, it would be expensive and usually unnecessary. Instead, what you want to do is identify your critical workloads and decide which ones truly need rapid failover. Maybe your customer-facing app gets replicated in real time, but your analytics data only gets backed up nightly.

You'll also need to think about data consistency between those environments. For example, if you're replicating databases, make sure your replication method aligns with your consistency model — whether that's strong or eventual. You don't want to fail over to a system that's a few minutes behind and corrupt a transactional workload.

And then testing is another big piece of the puzzle. A backup or DR plan that's never tested is basically wishful thinking. Both AWS Backup and Azure Backup let you run test restores without overwriting production data, and services like Azure Site Recovery include built-in failover drills so you can verify your RTO and RPO targets — you know, verify that they're realistic.

At the end of the day, a good backup and DR strategy isn't just about tools, it's about layers. You want local snapshots for quick restores, off-site or across-cloud backups for catastrophic events, and a failover plan that's been tested, documented, and automated as much as possible.

So remember that backups give you something to recover from, while disaster recovery gives you somewhere to recover to. Together they form the foundation of resilience in a multicloud world.

Backup and disaster recovery solutions

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