There is two types of interview questions for frontend developer: questions about CSS and questions about JS (duh). You need to be good at both of them in order to get job you want.

Beside of that if you're looking for good frontend DS developer you will want to ask him relevant questions about his field of expertise. Therefore if you're business owner or senior developer who is looking for new specialist you need some sort of list of questions in order to know where to start. Then this collection is also for you.

• CSS questions
• JS questions
• ES2015 questions
• HTML questions
• Your questions to them

Check also following links:

• Awesome interview questions for developers: https://github.com/MaximAbramchuck/awesome-interviews
• Frontend interview questions: http://www.thatjsdude.com/interview/index.html

Well, cause I don't like boring questions on the interview. Seriously, it looks like some employers just opened google, wrote "Javascript interview question" and something similar for CSS and just take random question from there. Since I'm considering myself as a professional, I don't like when my interviewer is not doing the same. There are a lot of questions that can help to evaluate level of the developer. It will be great if companies will start to think more about it.

Keep in mind that it is not effective to ask random questions, even if there are related to the tools your applicant will use. You need to ask questions that related to your code and your business needs. Otherwise you will hire some random guy with random skills. My aim here is only to give you some examples of good interview questions in general.