LinkedIn SSE Interview Experience

I recently went through an interview process for the SSE role at LinkedIn, which was a very insightful and comprehensive experience.

The first step was a Phone Screen, where I was given two coding problems. The first problem asked me to rotate a linked list by n nodes, and the second was to find the maximum sum subarray in a given array. I successfully solved both problems, explaining edge cases and detailing the time and space complexities to the interviewer's satisfaction. Shortly after, the recruiter called me to schedule the onsite loop.

My Onsite Round 1 (Coding) presented two more challenges. The first was to check if a graph is bipartite, given as a list of key–value pairs. I provided working code for this, but the interviewer suggested optimizing space usage by avoiding multiple arrays, and we ran out of time discussing this. The second problem involved processing logs with function names, start times, and end times to calculate the total and exclusive time taken by each function. I successfully solved this as well, delivering working code.

Onsite Round 2 (Coding) continued with two classic problems. The first was the Celebrity Problem, where I needed to find a person known by everyone but who knows no one in a given matrix. The second involved finding the maximum length of consecutive 1’s in a list of 0’s and 1’s, where some 0’s could be flipped. I tackled both problems efficiently, providing working code within the time limit and clearly explaining my logic, test cases, and edge cases along with their complexities.

The Onsite Round 3 (System Design) focused on designing an Exception Metric Collection and Alarming System. This system needed to handle millions of exceptions per second, support keyword-based searches, provide Top K frequent and least frequent exception queries, and include an alerting mechanism for specific thresholds. I felt this round went well; I was able to define functional and non-functional requirements, discuss scale, entities, and APIs, and propose a design that met the stated requirements. I did face a minor challenge with a follow-up question about Elasticsearch internals, as I hadn't worked with it hands-on, and couldn't answer it fully.

Next, the Onsite Round 4 (Technical Communication) was less about coding and more about my past large-scale projects. We discussed design decisions, trade-offs, technology choices, alternatives, and considerations for scalability and reliability. I thoroughly explained my project architecture and the reasoning behind my design choices.

Finally, the Onsite Round 5 (Host Manager Round) began with an overview of my past projects. We then moved on to why I was interested in LinkedIn and this particular role. The round also included a real-world design problem: building a system to collect feature button click counts and display aggregated metrics over time for Product Managers. I articulated my motivations for joining LinkedIn and how my experience aligned with the role, and for the design problem, I approached it methodically, covering data collection, aggregation, and scalability.

Overall, it was a great experience. Each round effectively tested different engineering dimensions, including algorithms, system design, and communication skills. I learned a lot throughout the process and thoroughly enjoyed all the conversations. 🚀