Begin a good programmer is not about being able to learn languages and frameworks. It is about being able to build solutions to complex problems. For these solutions to be efficient and reliable will almost always rely on good algorithms and appropriate use of data structures. Knowing the data structures exist is not enough. You need to understand the data structures will enough to use the right one for the problem. Lists and maps offer some valuable features, but they come with costs, and using the wrong one can significantly undermine the performance of your software.

A good interviewer knows this and is trying to determine if you can be valuable to his team or company. The language(s) you will be using 2 years from now may be very different, but the need for effective algorithms and data structures will not change.

Being a good programmer is not about being able to learn languages and frameworks. It is about being able to build solutions to complex problems. For these solutions to be efficient and reliable will almost always rely on good algorithms and appropriate use of data structures. Knowing the data structures exist is not enough. You need to understand the data structures will enough to use the right one for the problem. Lists and maps offer some valuable features, but they come with costs, and using the wrong one can significantly undermine the performance of your software.

A good interviewer knows this and is trying to determine if you can be valuable to his team or company. The language(s) you will be using 2 years from now may be very different, but the need for effective algorithms and data structures will not change.