Effective Backend Engineering Interviews

A question I ask in every interview

Effective Backend Engineering Interviews

A question I ask in every interview

On Interviews

The truth is engineering a problem seldom has one set answer. It is often challenging, muddy, confusing and time consuming. When the problem is solved almost always there is a drawback to the solution.

What makes a good engineer is understanding the limitation of the solution and working the entire stack around that. This is true for system design, architecture, troubleshooting or scaling.

It’s hard to know if the candidate is any good when I ask questions with pre-defined known answers. Like these:

• How to search a B+Tree?

• How to reverse a linked-list?

• What sorting algorithm is faster?

Sure these type questions are essential to get above the first bar, but doesn’t tell me much about the candidate.

Instead, my approach is to ask open-ended backend questions that don’t really have one answer. This way, I can tease out if the candidate is independent in analyzing the problem. Whatever tools the engineer knows they will attempt to use naturally, this tells me how knowledgable they are. If they talk about an area more than the rest of the system I know they are passionate about this area. If they skip a component I know they don’t know much about it or they are not comfortable in that component.

During the interview I’m not looking for an answer that I have in mind. I’m just observing and let the engineer walk me through it.

Let me take a concrete example question so I clarify my point more.

Example of a backend interview question