I admit I only skimmed the article, but I think the tradeoff of parting with the requirement of having an HTTP API with JSON as the message format for transport

I admit I only skimmed the article, but I think the tradeoff of parting with the requirement of having an HTTP API with JSON as the message format for transporting IDs over the wire, and just using Redis instead and its wire protocol, would probably have been the more time-efficient way to arrive at an (at least) acceptable solution for the problem they were looking to solve. But yeah, where's the NIH in that? ;)