Deno was announced on JSConf EU 2018 by Ryan Dahl in his talk "10 Things I Regret About Node.js".[1] In his talk, Ryan mentioned his regrets about the initial design decisions with Node.js, focusing on his choices of not using Promises in API design, usage of the legacy GYP building system, node_modules and package.json, leaving out file extensions, magical module resolution with index.js and breaking the sandboxed environment of V8.[9] He eventually presented the prototype of Deno, aiming to achieve system call bindings through message passing with serialization tools such as Protocol Buffers, and to provide command line flags for access control.