You can do high availability deployments using AWS. AWS offers different availability zones within a region, and multiple regions if you're extra paranoid. Unfo

You can do high availability deployments using AWS. AWS offers different availability zones within a region, and multiple regions if you're extra paranoid. Unfortunately the way reddit is using the available services is not ideal. IIRC they are using cassandra backed by EBS which is not a best practice. It's much better to run cassandra on local storage and have a backup system that's uploading incremental and full snapshots of your data to S3. I agree with your overall point that having a business continuity plan is required. They should be able to answer questions like how do we minimize impact when we lose one cassandra node or two, ebs gets corrupted, a whole avail-zone disappears, etc. I'm just saying that AWS provides the building blocks for you to do that.