Acing Technical Interviews

10 Apr 2016

Technical interviews are a pain. But here’s a 2-step plan to ace them:

1. Pick Java as your programming language du jour.
2. Use LinkedHashMaps.

The HashMap is great and usually the go-to data structure during an interview. But an interviewer who’s a jerk will always try to unnecessarily put down the HashMap. Here’s how that conversation might go:

Interviewer: HashMap, eh? But what if you want to keep the map to a certain size by removing the oldest entry when you hit the size limit?

You: Did you know about the LinkedHashMap method removeEldestEntry?

Interviewer: What if you want to have the performance of a map but you want to know the order things were put in?

You: Did you know keys can be iterated over in insertion-order? And before you ask - yes, you can iterate over the items in the order they were accessed.

Interview: Wow! You really know a lot! But can you reverse a linked list?

You: Yes I may know how to do something I would never actually do if you hired me, but did you know that internally the LinkedHashMap implementation maintains a doubly-linked list?

Interviewer: Wow! You’re great! When can you start?

You: I’ve already converted every pleb data structure in your codebase into a LinkedHashMap. *walk out*

Boom! You’re hired!