Background Users have been using Lucidchart for a long time to make their diagrams, since 2010 and IE6. And for nearly that long, Lucid has used Google's Closure Compiler to manage its increasingly sophisticated code base. Closure Compiler is a typechecker and minifier that uses JSDoc annotations in comments to understand type information. As Lucid grew from 5 to 15 to 50 engineers, the tool prove