D one is a. Curiable relational database that can be used to build on top of cloud flare, the CDN company behind Amazon's S three service. D one has its own V eight runtime so you don't have access to all node APIs. The free plan gives you 10 milliseconds maximum CPU time and if your code must run in 10 milliseconds, less IO network requests are required. But then when it goes over 50 milliseconds there's no time for local deployment or anything like that. It was just not possible to actually run it in that amount of time. And thankfully that was always one of the good things about moving to ES build is that that process got really easy.