Summary
I interviewed for an MTS 3 role at Cohesity India, completing three rounds focused on coding and system design. Despite a positive experience in some rounds, I ultimately received a rejection.
Full Experience
I was contacted by a recruiter over LinkedIn regarding an opportunity at Cohesity India. They clarified that, with my 5 years of experience, I was eligible for an MTS-3 role rather than MTS-4. The interview process was initially set for 4 rounds, but based on my performance, it was reduced to 3.
1st Round: Coding
This round focused on coding and my current project. I was given a variation of the 4 Sum problem and asked to code an optimized solution. The discussion and coding took about 40 minutes. Afterwards, the interviewer asked me to explain my current project in detail, grilling me a bit on its specifics. I felt this round could have gone better if I had been quicker in discussing the approach and coding.2nd Round: Design
This wasn't a typical system design round. The interviewer provided a brief problem statement: design a multi-tier cache. The tiers were specified as RAM (100MB), SSD (2TB), and then HDD, with increasing GET times across tiers. I gathered as much information as possible, and we finalized LRU as the eviction policy. We also discussed how to use a message queue to manage data formulation within each tier. This round went very well, and the interviewer seemed satisfied, even appreciating my proposed solution.After these two rounds, the recruiter informed me that I was being moved to a team matching/Hiring Manager round.
3rd Round: Director Round - Project and Code
This was the toughest round. The interviewer asked me to explain one of my projects in depth, inquiring about every detail, my responsibilities, and contributions. The first 45 minutes of this discussion went quite well. In the last 10 minutes, he asked me to come up with the low-level design code for the multi-tier cache, specifically in C++. Since I hadn't coded in C++ for three years, I was rusty and mentioned this to him, but he encouraged me to try. I attempted to write classes and interfaces, but due to lack of time, I couldn't finish. He mentioned he understood my approach based on what I had written and looked satisfied, saying the recruiter would contact me soon.The next day, I received a rejection email. I'm not entirely sure where things went wrong, apart from a couple of minor mistakes or instances where I needed the interviewer's help.
Interview Questions (3)
I was presented with a variation of the classic 4 Sum problem and tasked with coding an optimized solution. The problem required a thorough discussion of the approach before implementation.
I was asked to design a multi-tier cache system. The cache had specific tiers: RAM (100MB), SSD (2TB), and HDD, with the requirement that GET times would increase with each subsequent tier. I needed to consider eviction policies and data management strategies across these tiers.
Following the system design discussion, I was later asked to provide a low-level design and implement a portion of the multi-tier cache in C++. This involved coding classes and interfaces for the cache system.