SWE (L4) Interview Experience at Rubrik (2025)
Summary
I recently interviewed for a Software Engineer (L4) position at Rubrik, undergoing five rounds focusing on system coding, algorithms, system design, and a hiring manager discussion. The process heavily emphasized multithreading, concurrency, and OS fundamentals, and I am currently awaiting a response from the recruiter.
Full Experience
I recently attended five interview rounds for the SWE (L4) role at Rubrik, which focused significantly on multithreading, concurrency, and synchronization techniques, along with OS fundamentals. The structure was as follows:
- System Coding 1: This round delved into concurrency, multithreading, process management, memory management, and synchronization concepts. I was asked to design a job scheduler that efficiently runs jobs with dependencies, assuming a function to get available jobs based on finished ones.
- Algo Coding: This round featured a Medium to Hard LeetCode-style question. I received a stream of data and for each new item, I needed to return the minimum absolute difference between any two elements among the last K elements in the stream.
- System Coding 2: The problem here involved designing a system for a playground accessible by only one team at a time, with a maximum of 10 concurrent players. The challenge was to manage multiple players from different teams trying to access it simultaneously, while also preventing player starvation.
- System Design: I was tasked with designing a system similar to LinkedIn Connections that could efficiently answer queries about the degree of connection between two users (e.g., 1st-degree for direct connections, 2nd-degree for friends of friends) for up to 1 billion users.
- Hiring Manager and Technical Deep Dive: This final round was a deep dive into one of my past projects, where I discussed challenges faced and decisions made. It also included several behavioral questions.
Interview Questions (4)
Design a job scheduler that runs all available jobs in an optimized manner, considering job dependencies. You can assume the existence of a function get_next_jobs(finished_jobs) that returns all jobs whose dependencies are fully satisfied based on the currently finished jobs. A job can only be executed after all of its parent (dependent) jobs are complete.
You will receive a stream of data. For each item, return the minimum absolute difference between any two elements among the last K elements in the stream.
There is a playground that can be accessed by only one team at a time, with a maximum of 10 players allowed concurrently. Multiple players from different teams may attempt to access the playground simultaneously. How would you design the system to assign players to the playground while enforcing these constraints? (They will ask about different approaches you can take to avoid starvation of any player)
Design a system similar to LinkedIn Connections that can answer the query: "How many levels (or degrees) of connection exist between two users?" For example, direct connections are 1st-degree, friends of friends are 2nd-degree, and so on. The system should efficiently handle up to 1 billion users.
Preparation Tips
To prepare for these interviews, I concentrated on mastering fundamentals, particularly in multithreading, concurrency, and OS concepts like memory management and process synchronization. For the system coding rounds, which differed from typical FAANG interviews, I gathered recent interview questions from platforms like LeetCode and Reddit. My approach involved solving one question at a time, identifying all necessary underlying concepts, and then studying those concepts in depth. I found it beneficial to treat the interviews as discussions, focusing on sharing my opinions and reasoning rather than just finding a perfect solution.