I applied to Amazon back in September and got an OA near the end of December. If you’re reading this then you’re probably worrying about your upcoming Amazon OA. Fear not, I passed those OAs with flying colors and got an interview!

OA 1: Debugging

For the first OA, it really is just debugging. You look through lines of code to see what the problem is and they only give you the option of coding in Java, C++ or C, so if you’re only familiar with Python, now’s a good time to learn syntax for one of these other languages.

These debugging questions aren’t meant to be hard because they only give you 20 minutes for 7 questions (which is a little less than 3 minutes per question). Usually you’re correcting <, >, = or ||, &&. 

Even though you only have 20 minutes, if you start panicking then, you might run out of time. A great website I used to help me prepare for this is aonecode. Literally practiced the night before and finished my OA within a few minutes.

OA 2: Technical Assessment and Leadership Principles

The second OA is determining your technical abilities. You get 90 minutes to complete two questions (I’d say leetcode medium). There are a ton of leetcode discussions that list out what questions Amazon has given in the past and people are kind enough to give solutions. Though, I would try to tackle problems on your own before looking at answers.

After your technical assessment, you’ll take a leadership principles survey. Amazon’s website has the backbone of what their LPs are, but this website helped me most. He really explains the LPs in more depth. I left it open to refer back to it and it definitely helped.

OA 3: Work Simulation

Amazon’s work simulation is exactly what it sounds like. You work a day (or a few hours) making decisions like an Amazonian. They explain the process and I can’t go into great detail on how to succeed this part. BUT having the LPs open (and the article above) to refer back to really helped.

Interview

So there’s two interview types: a single 30 minute interview (the meme interview) or three 45 minute interviews back-to-back. 

Meme Interview

This interview is literally just going over your OA 2. If you do get this one, then apparently it means that Amazon is 99% sure that they are going to hire you, they’re just making sure that you can communicate well. I can’t go into this because I got the standard three 45 minute interview, but I’m sure as long as you explain your thought process and communicate well, you have nothing to worry about!

Standard Interview

I was unfortunate enough to get the three 45-minute interviews. These are 2 leetcode (easy/medium) problems and an OOD question with a behavioral question at the beginning of each interview. Some people have gotten a hard leetcode problem instead of an OOD question, so just prepare!

They’re really just looking to understand your thought process, so as long as you can solve the problem and walk the interviewers through, I’m sure you can pass the technical part. Make sure you think of all edge test cases (if your input is an array, what happens if it’s empty?). 

Justin Lin helped me and explains how to approach the interview. He even shares his own cheat sheet on what to talk/think about! Highly recommend checking him out!

I wish you all the best luck in your interviews and OAs!