Should you build or buy Disaster Recovery & DRaaS?
Disaster recovery and DRaaS software replicates servers and data to a second region or site and packages the failover, failback, and testing workflow needed to keep running through a regional outage. Enterprises running virtual machines or cloud workloads with real uptime commitments buy it to meet recovery time and recovery point targets.
Buy DRaaS for VM-heavy or tightly coupled estates where point-in-time recovery, cross-VM consistency and routine drills matter, and choose on measured RTO/RPO in your own test, not the datasheet. Use native database replication and IaC for cloud-native applications your team already operates multi-region, and fund the failover and failback ownership permanently.
Build it, buy it, or bridge?
When building makes sense
Athenahealth is the clearest documented case of a company building and testing its own disaster recovery. After a 2025 AWS regional outage made its single-Region Terraform Enterprise deployment inaccessible, athenahealth worked with AWS and HashiCorp over five months to design a multi-Region architecture using Aurora global databases, bidirectional S3 replication, and Route 53 health-check failover, then validated it with AWS Fault Injection Service experiments rather than trusting the design on paper. The result was a measured 12-14 minute recovery time and under one minute of data loss, confirmed through chaos testing that also caught a stale AMI reference and a database connection-pool misconfiguration nobody had noticed. This is a real, working build, but it covers one cloud-native application with a team already expert in that stack. Building clears the bar when you're protecting cloud-native workloads your team already runs multi-region, not a VM estate that needs cross-VM consistency and drills a small team can't validate every quarter.
When buying makes sense
AWS Elastic Disaster Recovery bills a flat $0.028 per server per hour, and its own published example for 100 servers replicating 30 terabytes totals around $230,000 over three years, a modeled self-built equivalent on comparable infrastructure comes out at $201K-$269K, so there's no clear cost win to building for a typical VM estate. What packaged DRaaS actually buys is the workflow: Zerto delivers continuous journaled replication with recovery points seconds apart, Azure Site Recovery sequences multi-VM recovery plans at roughly $25 per instance per month, and Druva provides backup-based recovery in 10-30 minutes. These products exist because point-in-time recovery, cross-VM consistency, and repeatable drills across dozens or hundreds of VMs are hard to build and harder to keep tested. Resilience is an obligation, not a competitive edge, so buy the packaged workflow for VM-heavy estates. Choose the vendor on your own measured RTO and RPO test rather than the datasheet.
The desk read
Build-versus-buy analysis for Disaster Recovery & DRaaS is being written. In the meantime, the framework that drives every B4 call is on the B4 Index page.
Frequently asked
What is disaster recovery and DRaaS software?
DRaaS replicates servers to a second region and packages the failover, drill, and testing workflow needed to hit recovery targets during a regional outage. AWS Elastic Disaster Recovery bills a flat $0.028 per replicating server per hour, with no minimum commitment.
Has any company actually built and validated its own DR successfully?
Yes. Athenahealth designed a multi-Region DR architecture for Terraform Enterprise on AWS after a 2025 regional outage, then validated it with AWS Fault Injection Service chaos experiments and achieved a measured 12-14 minute recovery time with under one minute of data loss. The build took a five-month cross-team engagement.
Is building cheaper than buying DRaaS?
Not clearly. AWS's own 100-server DRaaS example runs about $230,000 over three years, and a modeled self-built equivalent lands at $201K-$269K, roughly the same range. The build case is about control and cloud-native fit, not cost savings.
When should a company buy DRaaS instead of building?
For VM-heavy or tightly coupled estates that need cross-VM consistency and drills run routinely enough to trust. Packaged tools like Zerto and Azure Site Recovery exist specifically because that workflow is hard to build and expensive to keep validated with a small team.
What are the main disaster recovery and DRaaS vendors?
Representative vendors include AWS Elastic Disaster Recovery, Azure Site Recovery, Zerto. B4 Pro includes the category score and the full vendor list.