In my experience, closures are a topic that always comes up. It is also important to know how to handle a closure inside of a for loop. I've been asked about "this" binding, coercion, and CSS specificity. I've had to solve problems that required me to know about how to use stacks, trees, and nested for loops. Other topics that have come up are how to architect an app, concurrency, memoization, building out and handling api endpoints, and pass by reference vs. pass by value.
You may not think databases are a front-end topic, but I have been asked about them on more than one occasion. Prepare to talk about sharding, natural primary keys, what your favorite database is and why, etc.
Something that has been extremely useful for me is to have a project that I've built myself to show and talk about during the interview. Although I have had one interview where I was asked to talk in detail about how I built some of my projects that are in my github, I like to respond to general technical questions while referencing something I've built. A lot of times the interviewer will then use my app as a starting point into a discussion for how I would scale it. Here's an example of an app I built quickly and have used for discussion in interviews: http://moviemap.xyz/ More here: http://valeriemettler.com/
You may not think databases are a front-end topic, but I have been asked about them on more than one occasion. Prepare to talk about sharding, natural primary keys, what your favorite database is and why, etc.
Something that has been extremely useful for me is to have a project that I've built myself to show and talk about during the interview. Although I have had one interview where I was asked to talk in detail about how I built some of my projects that are in my github, I like to respond to general technical questions while referencing something I've built. A lot of times the interviewer will then use my app as a starting point into a discussion for how I would scale it. Here's an example of an app I built quickly and have used for discussion in interviews: http://moviemap.xyz/ More here: http://valeriemettler.com/