Amazon OA round : No one talks about

I recently gave the Amazon OA and that round hits different. In this article I will discuss each round in detail , what problems no one talks about and how to prepare for it.

Amazon rounds include:

1. DSA

2. AI assistant Debugging

3. Work-style assessment

1. DSA [40 mins] :

Note: There is something most people will not talk about. They give a clock that ticks every second and this automatically creates silent pressure no matter how well you are prepared. So ignore the clock initially and understand the problem first.

In my assessment a hard level string problem came where I had to dynamically store strings in a vector and return the vector size. The problem was very tricky.

This is where most people either found it easy or tough. Honestly I will say that Amazon does not provide medium problems every time so stop saying the term medium level problems.

It is more about can you solve any unseen problem. Then every problem automatically seems like easy-medium.

To gain that level of confidence we must stretch our thinking on the topics of String, Array and HashMaps by solving hard level problems.

The equation is easy.
For general topics like Array, Strings and Hashes solve hard.
For Binary Search, Linked List and Stacks solve medium to hard.
And for Trees, Graphs and DPs solve easy to medium because they have very common patterns.

Amazon does not give you a problem that has any particular algorithm.

2. Codebase Debugging (60 min) :

They gave a medium level codebase. For me it was a movie app with React frontend and Node backend.

The problem was simple. In their search box where we search movies with filters and advanced filters like date, category, actor or actress we get errors because the Search API is broken at 6 places.

You do not have to solve all 6 cases.

I know the clock will tick. I am giving you some tips so that you will not get lost in the codebase initially.

Tip 1: Do not invest time on the whole codebase. You will have the error in any particular API in the backend.

Tip 2: Immediately run test cases to see where exactly the error comes and copy paste those errors to the given AI. It will search the exact file and code for you. Use your AI smartly.

Tip 3: First compare your API parameters with the models (DB fields) because there you will probably get the first errors like spelling mismatch or missing fields.

Tip 4: Always scan all errors and sort them based on easiness else you will end up solving only 1 hard test case. Check what test case is easier to solve and attack it.

For AI: Do not waste time to prompt engineer the AI and expect it will help. No it will not. The AI will just find you the code, the wrong thing and sample code structure. At the end of the day you have to write the code yourself.

How to practice before OA?

Of course attempt their mock test. It will give real OA experience. But remember mock tests are much easier than the real test. In the mock you are supposed to have only 2 errors to debug.

Find your previous project and prompt AI not to write code or give direct solution. Just find a bug. If no bug is present then somehow make any API buggy without noticing the changes and try to solve it yourself. It will not give surety but it will boost your confidence.

3. Work-style [No time limit] :

This hits most interestingly and this is where most people who cleared the previous 2 rounds still end up getting rejected. Give dedicated time for it.

It will give you an email box like interface where you will play a game of what you do for your colleagues emails.

The only way to clear this round is research about Amazon’s Leadership Principles and keep them in your mind. Link every tricky answer to those principles and just make them your answer. Do not try to be unique at that moment.

If for your mindset shipping fast and improve later is the best approach do not proceed because Amazon cares about their 1 percent (millions plus) customers so they prefer to delay launch. So do not try to be real.

You can also find lots of practice problems on YouTube. Just watch them and understand.

In the last round you just need to be consistent and match with Amazon’s principles. That is it.

Reply to comments. I will answer any questions.