DE Shaw Interview Experience

Hey Geeks, I am writing down my interview experience with DE Shaw. I applied through the carrier portal of DE shaw. I received a test link after more than a month. The total process consisted of 4 rounds(Coding test, Screening Round, On-site-1, and On-site-2).

Coding Test: This round consisted of 3 coding problems, 10 MCQ on CS fundamentals, and10 MCQ from Aptitude. I was able to solve the 2 Hard problems of 40 marks each however I was not able to solve the first one.

1. The first one was: 2 players play a game with some starting number N. At each step each one will subtract a perfect square from the starting number until it becomes 0. The person playing the last move wins. Predict the winner for a given starting number N. N <= 1e6.
2. Second One: https://www.geeksforgeeks.org/bell-numbers-number-of-ways-to-partition-a-set/
3. I don’t remember the 3rd one.

MCQs were easy.

Screening Round:

1. Find max consecutive one.
2. Similar to the minimum number of platform problem. But you also need to tell the platform number for each train. You are given an array of [{Train_Number_1, Arrival_time_1, dept_time_1}].
3. What is normalization in dbms?
4. B-tree vs B+ -tree
5. Indexing and Index Table.
6. Virtual keyword, Vptr,  vtable

Onsite Round 1:

1. Given an array of binary strings. Find the largest subset of the string such that the max count of zeroes is m and that of ones is n. They made me write the code.
2. Related to project.
3. Median of a stream on integers. I replied instantaneously so they added a delete number operation to makes things hard only logic was required at this stage no coding.
4. Given 3 arrays. A, B, C. Find i, j, k such that A[i] + B[j] = C[k].

No CS fundamentals in this.

Onsite Round 2:

Some HR-based questions. 

• Very friendly interviewer in this round. 
• They asked about the famous browser history problem. They wanted a DS-based. solution. Since I have some development experience I gave them an elegant solution they were a lot impressed with me. He also said excellent.

The second interviewer asked me CS fundamentals and project-related.

1. How react.JS works. VDOM.
2. How JS being single-threaded performs multithreading.
3. Process vs Threads.
4. Multithreading vs Multiprocessing.
5. CPU intense task vs I/O intense task which will you prefer.
6. Some more rapid-fire questions were also there.

This marks the end of the process.

Verdict: Selected