Over the phone, they might ask you, if you were working with a customer, how would you develop a product with them? Answer that you would basically ask the customer questions to determine exactly what it is that they want and then you would make a mock. You would then work with them to see if that mock is acceptable and then you would basically identify the key features that they must have. Then you would work on a prototype and basically you would work on it in a manner in which it is flexible and can be built upon in an iterative approach because things can change so fast in the industry and so can a customer's demands.
In the in person interview, I had to take some test, which was basically solving some puzzles. I had to do some whiteboard process where they asked me how to go about the process of creating a form that would be able to transmit a CC number. I could use angular or whatever. So I just walked through that. They pulled up my blog and I talked about that. Went through some of my code on github and I showed them a site I deployed. They asked me what I liked about Angular 2 since that was what they were using. They asked me a bit about responsive web design and how to go about it, and basically I answered with a very general overview of media queries.
If you're applying for a web development type position, I think the key more than anything is to know the basics of HTML, CSS and Javascript and also have some kind of online presence, which will include a site you've deployed and possibly a blog. Sometimes they do go through and read what you write and that can make you stand out.
Each stack has so many different pieces to it that it's not possible to know it all, so if you don't know something, don't try to dance around the issue and give some made up answer. Just say I haven't familiarized myself with that particular library yet, but I learn quickly. The basic impression you want to give off is that although you might not know the particular library they are using, you can pick it up very quickly because you are a fast and eager learner. Now you can only do this if this is not the main library that is in the job you are requesting. For example, if it is an Angular job, you need to know Angular, but when it comes to a minor tool, for example, such as if they are using a task runner like gulp and you are familiar with grunt, tell them that you've used grunt before and you would just need a little time to learn the syntax of gulp.
Also, what will make you stand out is if YOU ask decent questions. Ask them about why they chose this or that in their particular stack. If you don't know a particular technology that they are using, maybe ask about what would be some great books to learn that particular piece of tech. Basically, you want to give off the impression that you actually love programming and you aren't just there to pick up a paycheck.
So basically what I"m saying is to actually deploy sites and give them the impression you know how to create something and that although you may not know every particular element of their stack, you are willing and able to pick it up on your own very quickly. Also, learn a testing framework. Tests are big now. Having that knowledge will make you stand out.
