Front-end: Fundamental questions about JavaScript. They don't care whether you know Angular, React, or Vue.js. As a smart company, they realized that a good developer can easily switch between libraries/frameworks if given the room to do so. I was challenged with a really fun set of questions that lead to one another within JavaScript. The interviewer was genuinely interested to see how I think, and didn't care much about how precise my code is. Practice on your deep JavaScript understanding and you should be alright. Make sure to be aware of all the quirks of JavaScript.