BlackRock visited our campus (VIT, Vellore) on 1st September 2020 for hiring. The role offered was a Technology Analyst (Intern) and Financial Modelling (Intern / Intern + FTE). For those filling in for Financial Modelings, they had a prerequisite of being good in Data Science and Machine Learning. I applied for the Technology Profile.
Eligibility: All Branches & CGPA above 6.0
Round 1 (Online Test): This round was conducted on a site of their own and the time duration for this round was 90minutes. It was a very well segregated test with emphasis on all aspects of Aptitude, Algorithm Design, and DBMS.
The test was divided into 3 major sections – Aptitude, Programming Ability, and SQL
- Aptitude: The aptitude section consisted of various subsections like Logical Reasoning, Attention to Detail, Advance Aptitude, Data Interpretation. All of these sections were timed to the very limit of one minute per question. Logical Reasoning had 8 minutes for 5 questions, Attention to Detail had 9 minutes for 8 questions. The timing is very important here. My advice would be to practice Advance Aptitude, Data Interpretation, and Logical Reasoning before sitting for this round. Attention to Detail is something that will not require any preparation. All you have to do is read a bunch of closely related numbers and find which of the options had the wrong combination. You can practice quants from this GFG article.
- Programming Ability: It had 15 questions to be done in 30 minutes. If you have a good grasp of concepts and a knowledge of how to design an algorithm for a given problem statement – you’ll be done with this in under 20 minutes. The first 12 questions were of the form. There was a problem given and a worded solution was given along with a flowchart that had empty spaces numbered from 1 – 5. The questions were to fill what would be in those blank spaces. The last 5 questions were from AVL Trees.
- SQL: It had 15 questions related to databases. They were like the advantages and disadvantages of databases like MongoDB, syntax related questions, and some questions related to giving the SQL query for the given output and vice versa. This was a 30 minutes section of 15 questions and it was easy too.
Out of 700 students that appeared for the Technology Profile 150 were shortlisted for the interviews.
Round 2 (Technical Interview): This was conducted on the Cisco Webex time duration for this round was 1 hour. My panel consisted of two members from the Technical team at Blackrock. One of the members in my panel was a VIT alumnus. Here’s how the interview went
They introduced themselves and told me to do the same. I did. During my introduction, I shed some light upon my internship work done last summer, and the first interviewer began with that.
1st interviewer: Tell me more about your internship.
I told him about how I processed the data, extracted text, and kept mentioning the technical terms along as I was proceeding forward. I told him about the objectives that I intended to achieve through the application I was building and some challenges I faced and how I managed that.
1st interviewer: How did you manage to extract names and identity numbers as they were not in key-value pairs?
I told him I used a certain text as my fixed point and iterated over all the texts detected below it. Gave him an example too. He was convinced by the response and said, “That project sounds really cool”. Then he passed on the control to the other interviewer
2nd interviewer: You have mentioned web-dev projects in your resume. Can you tell me about that?
I am not a web-dev person and those were semester projects. I told them that they were basic projects done during the course of the semester and still explained all that I knew about it. She felt pretty convinced and told me that she won’t go on the web-dev side and ask me about the technology used.
2nd interviewer: Why MongoDB?
I told her that I wanted to work with NoSQL databases and between Google Cloud Firestore and MongoDB, I went with MongoDB. Followed a Youtube tutorial to make a CRUD app and then coded my backend.
2nd interviewer: Can you explain the difference between MongoDB databases and traditional SQL databases? There’s a major architectural difference between them.
At first, I was confused about what to answer, but then when he mentioned the “architectural difference”, I thought I should go with the difference between SQL and NoSQL databases. I explained the differences – told them I preferred NoSQL for my projects told them the advantages of NoSQL over SQL – some disadvantages too (have to program constraints than have the Db to do it). They were happy with the answer. Now, we moved to certain coding questions
2nd interviewer: I have 2 strings – A and B and I want to know if B is the anagram of A or not?
They asked me to share my screen and code the solution in any IDE as a complete Java program. I started off by explaining the solution that came to my mind first. I used HashMap to count the characters in A. Then iterated over B and started decreasing frequency. For characters whose frequency reached 0, I removed it completely. Finally, I checked whether the map was empty or not. I also added a pre-checking of lengths before execution too. They weren’t completely satisfied with the solution. They asked me to optimize it using less space. At first, I was not aware of the solution, but then they gave me a hint – “Sorting”. It was then where I remembered that characters in anagrams must have the same alphabetical order. I explained the solution and they were now satisfied. However, they weren’t completely satisfied because they had to give out the hint.
2nd interviewer: Why BufferedReader over Scanner?
I told them that the Scanner is not that efficient because of tokenization errors and it is slow compared to BufferedReader. Also, BufferedReader is a thread-safe. Then, I gave them a difference, my computer teacher told me in my 9th standard, and we shared some laughs on it.
2nd interviewer: Can you implement Stack using Queues? Just explain the solution using a sample I/O.
I explained how I would use 2 Queues and implement them.
2nd interviewer: Why are you dequeuing all elements from Queue 2?
I told them that the output required LIFO and Queue has FIFO architecture. This was the answer they were looking for.
1st interviewer: Why HashMap? (referring to the String question they asked)
I listed some advantages and disadvantages of HashMap along with certain theory concepts.
Then they asked if I had some questions for them? There were my questions:
- (To my college alumnus) How was your experience at VIT?
- (To both) How is life at Blackrock?
- (To both) Any advice you would like to give to a fresher who is joining Blackrock?
I got a call from their HR department about an hour later telling me that I was selected for the final HR round. it was in about an hour and a half.
Round 3 -(HR Interview): The time duration for this round was 30-40 minutes. Basically depends on how you answer elaboration or keeping it short.
This was a pretty good interview. It was more of a discussion where my interviewer wanted to know about me and whether I would fit in the company or not. He introduced himself and asked me to do the same. Then the questions were as follows:
- Tell me about your projects and your internship. What did you learn from them? Both personally and professionally
- What do you expect from a company that is about to hire you?
- Are you a team player or an individual player?
- Your short term and long term goals?
- Plans for PG (postgraduate) studies?
- Any location preference?
Then, he asked if I had any questions for him? I asked about life at BlackRock and told him that I liked the fact that an alumnus of my college took my interview. We had some laughs and then he ended the interview
Results: The results came out the next day, and I was selected for the Internship.
Here are a few tips from my side for students appearing for the interview –
- Be cool when you are answering. Your nervousness shows that you are not confident about what you are answering and you’ll lose points even if you presented the right answer.
- Make sure you are clear on the projects you mentioned on your resume. Also, state your proficiency level in the technology used in the project. This will help if you are slightly weak in the technology you used.
As for resources, I think GeeksForGeeks is enough for learning the concepts. You can go through their article on Algorithms and Data Structures along with the theory for the language you prefer. For practice, I recommend Leetcode and HackerRank.
If you want every basic thing in one place – here you go!!
You can visit GATE CSE -LMNs for your last-minute preparation.
All the Best!!