Morgan Stanley

Role: Senior Associate (Backend)

College: Not Specified

Interview Date: Not Specified

Interview Type: Experienced

Result: Selected

Difficulty: Hard

Rounds: 3 rounds

Topics Asked: Coding (Data Structures, Algorithms), Group Activity (Business Ethics, Teamwork), Projects, Data Structures (2D Matrix, Median, Random Number from Stream), Algorithms (Stock Trading), System Design (In-Memory Database, Indexing, DBMS concepts), OOP (Maps, Collections)

Experience:

This experience is for an experienced role (2.5 years experience) during a hiring drive.

Round 1 (Coding Round - 45 Minutes): Two problems were to be coded.

• Problem 1: Hierarchy print based on a string. Given employee-manager relationships, print the complete hierarchy for an input employee (e.g., Rahul -> Mohan -> Ajay -> Ramesh).
• Problem 2: Reverse words of a string based on the Fibonacci Series. If a number is duplicated in the Fibonacci series, don't reverse that word (e.g., Input: "zero one one two three four five six seven eight nine ten" Output: "oerz one one owt eerht four evif six seven thgie nine ten").

Some candidates were shortlisted after this round.

Round 2 (Group Activity): Similar to Morgan Stanley's legacy, candidates were given pictures and asked to come up with an idea to impress investors, focusing on business ethics. Advice: actively participate and offer new ideas without suppressing others.

Round 3 (F2F Technical - 1 Hour): A pure technical round. It started with a project discussion, where the interviewer gave conditions and asked the candidate to resolve them using their previous company projects. Three data structure questions were then asked:

• Question 1: Given a 2D matrix of 1's and 0's, find the max square with boundaries as 1's.
• Question 2: In a stock market, prices change hourly. Provide the full channel of buying and selling stocks to maximize profit. If you buy a stock, after selling it, you can buy another. You cannot continuously buy.
• Question 3: Given an infinite stream of numbers, find the median at any point in time without using extra memory. The question was then changed to printing a random number from an infinite stream.

The interviewer then asked about Cassandra's internal workflow (as the candidate had worked on it). Following this, a system design question was posed: design an in-memory database that is scalable and sustainable, can handle any query, and provides data based on those queries. Questions on indexing, primary key persistence, deletion, and insertion in the database were asked, along with B+ tree and B- tree concepts. Finally, questions on collections and the internal structures of HashMap, TreeMap, and LinkedHashMap were covered.

After 2 days, HR called, and the candidate was selected for a backend senior associate position in the Prime Brokerage Funding & Finance Technology division.