I was also alarmed to see that dynamodb:DescribeStream is limited to 10 QPS per account, making low-latency stream consumers into noisy neighbors of each other.

I was also alarmed to see that dynamodb:DescribeStream is limited to 10 QPS per account, making low-latency stream consumers into noisy neighbors of each other. Then there's all the "open a support ticket" per-account limits on table provisioning and running EC2 instances…