content: As a Javascript dev I've experienced this for around 7 years straight. JS technologies I've ended up learning and having to maintain the resulting work in roughly chronological order.  Plain JS/ES5 Protoype Dojo jQuery HTML & CSS Prepr  ffa  ocessors Canvas/SVG/Video/PDF Frameworks (e.g. D3/Mozilla PDF/Easel/Video and on and on) jQuery UI Backbone Knockout Coffeescript Grunt Bootstrap NodeJS (0.x-7.x) NPM, Bower Angular 1 Gulp CSS Postprocessors Cordova Material Design ES6 Meteor JS Webpack Angular 2 (/4) Typescript Serverless & AWS (huge black hole, prob a dozen technologies with heavy docs)  This is a portion of the JS turnover I've seen. Not even counting accessibility, internationalization, backend research when you need to change APIs, command line learning, SSH. I guess that's why they pay so well now ;-) I'm not complaining, but fuck I get burnt out like 3 times a year.