I'm not one to prematurely optimize things, but I'd be cautious about blindly copy/pasting some of these solutions unless you want your coworkers to make fun of

I'm not one to prematurely optimize things, but I'd be cautious about blindly copy/pasting some of these solutions unless you want your coworkers to make fun of your O(n^3) set intersection algorithm: array.reduce(function(a, b) { return a.filter(function(value) { return b.includes(value); }); })) https://github.com/you-dont-need/You-Dont-Need-Lodash-Underscore#_intersection https://github.com/you-dont-need/You-Dont-Need-Lodash-Unders...