Amazon SDE 1 Interview Experience

Summary-

Round1: Test consists of 3 parts with 60 questions 90min. Marking scheme is +4 & -1.

Round2: Technical interview1 (30 min)

Round3: Technical interview2 (30 min)

Round4: HR (15 min)

Detailed-

Round1(Online Test) – There is a different qualifying cut for each section.

The test consist of 3 sections: All need to attempt in order, we are allowed to switch between questions of the same section but cannot switch between sections.

Section1: This section consists of basic aptitude questions like train, permutation & combination, probability, boat, work, etc.

Section2: This section contains the questions of code snippet(given a code what is the output)

Section3: This section contains basic Gate level questions mainly focused on DS, Algo, OS, CO, Networks.

Round2(Tech interview1) – It was a one to one interview. He asked me to write pen-paper codes, questions from C, OS, CO, etc.

Questions:

1. Reverse a stack without using extra space.

2. Construct a tree from pre-order and in-order traversal.

3. Given an array which has numbers from 1 to n. There are 2 numbers replaced with 0. Find both numbers in O(n) time and O(1) space.

4. What is priority inversion?

5. Let us suppose there are multiple .c files and you want a function from a particular file can only be accessed in that c file only. (Ans- Use static keyword)

6. What is Volatile keyword?

7. A lot of questions from IPC, Cache, Paging.

Round3(Tech interview2) – It was also a one to one interview. I was the last person left for round 2 and it was around 9 pm, so everyone was drained.

Interviewer: Do you know how to construct a balanced tree.

Me: I only know that we can use a red-black tree or AVL tree, but I don’t know how they work.

Interviewer: Ok, then what do you know in Algorithms.

Me: Sorting, Graphs.

I want him to ask from graphs but he started with Linked list.

Questions:

1. He asked all the possible questions from the linked list starting from construction of SLL to finding loops etc.

2. Then he asked me questions from C programming, OS, CO.

Round4(HR) – This was more of one-sided. HR told me about the company asked me about locations preferences etc.

Both round 2 and 3 last up to around 30min. All the questions were basic level instead of 2-3 fancy terms that I ended up answering “I don’t know”.

Suggestions- They asked a lot of questions from oops, data structure, C programming, os, co, etc. One panel was also asking questions from ML like PCA, LDA, SVM, etc.

They also asked riddle-like(google them for details)-

1. King and 100 poison bottle

2. Bridge crossing (person with different time and one torch)

3. Measure time from the rope, sand clock, etc.

Note: There were other questions that I don’t remember.