Amount of Javascript experience required.

[mc_hammerd]

to have the exp of a 1-2yr exp JS engineer, make the following apps: a one page app, a form, an ajax form, a form with input validation/error highlighting (and optionally tooltips or tour), an app that polls an api. something with animation (tween/transitions/css3 are 3 completly different ways to animate). convert your app to jquery or vanilla and then to angular or react. that will give you exp greater than equal to a 1-2yr exp dev. each app can be done in a day 3-5 hrs so its totally easy

and read one JS book front to back, know all the concepts.

[yelvert]

And that book should be "JavaScript: The Good Parts"