3 months. I'll tell you, I started with web dev in late 90s. At the time there was no CSS, most JavaScript was called DHTML and you worked with what was availa

3 months. I'll tell you, I started with web dev in late 90s. At the time there was no CSS, most JavaScript was called DHTML and you worked with what was available at the time (eg. tables for layout). There was also a full-front browser war going on, no web standard at all. Just to be proficient with CSS, it took me years. A steady but very slow learning curve. And CSS was painful at the time (no flexbox, no standard box model). It took serious efforts to just render a PNG image with alpha! ES6 is syntactic sugar! It will give you some productive advantage but you should focus on how to solve problems first, no matter the tools under your belt. Even today I google everyday docs for the most used or basic functions I can't remember a parameter order or what they returns, this has nothing to do with your programming skills. Today front-end is a very vast landscape, with an absurdly growing ecosystem. No way you can master all of it in 3 months. Also, we're past the point were you can (or must) follow every paradigm or framework, there are no common best practices and you must make important choices, some of them will make or break your career, or at least will push you back. 3 months will just get your feet wet. If you really want to do this, you'll have to find a junior position and spend the first years of your career just learning, while working. No matter how long, intense or immersive, no course or tutorial can give you the experience you need.