He's talking about building the underlying failover mechanism for CosmoDB. For a customer it's easy and automatic, but GCP and AWS and Azure have to build it first.
FTA: "if _you_ are an engineer working on a small thing, say datacenter automatic failover component" (emphasis added). Pretty sure he's talking about EVERY customer spending months to turn on fail-over.
"if you are an engineer at Microsoft working on a small azure component, say datacenter automatic failover component"
At least this is how I read it since the OP works at MS it appears.