Linkedin | SSE | Oct 2025 | Rejected

I interviewed for a Senior Software Engineer (SSE) role at Linkedin in October 2025. The process involved multiple rounds, and despite strong performance in some areas, I was ultimately rejected.

Round 1 - Technical Problem Solving (TPS)

This round involved a mix of technical discussions and a DSA question. I was asked to:

• Discuss any issues I've found in systems during my work, such as performance bottlenecks or poor code quality.
• Share my mentoring experience.
• Explain software design patterns and their importance.
• Describe the CAP theorem.
• Differentiate between concurrency and parallelism.
• Determine the output of a given multithreading code snippet.
• Solve the "Diameter of a Binary Tree" problem.
• Design an API capable of handling 10,000 queries per second (QPS) for write traffic.

I received a "Hire" verdict for this round.

Onsite Rounds

Round 2 - Data Structures & Algorithms (DSA)

In this DSA round, I faced three problems:

• An adaptation of Insert Delete GetRandom O(1), specifically focusing on implementing a removeRandom method.
• A follow-up based on Insert Delete GetRandom O(1) - Duplicates Allowed.
• A problem conceptually similar to Number of Islands, but presented within a real-world story context.

I received a "Strong Hire" verdict for this round.

Round 3 - Data Structures & Algorithms (DSA)

This DSA round had two problems:

• Closest Binary Search Tree Value II: I could only develop an O(N) solution, while the interviewer was looking for an O(logN) approach using predecessors and successors.
• Intersection of Two Linked Lists.

The verdict for this round was "No/Lean Hire".

Round 4 - High-Level Design (HLD)

I was asked to design a notification system. This involved considering aspects like rate limiting for different notification categories (e.g., 5 marketing notifications per day per user) and handling user preferences. Additionally, there was a discussion on how I measure project success, including performance testing and metrics like p90.

The verdict for this round was "No/Lean Hire".

Round 5 - Hiring Manager (HM) & Behavioral

This round covered a mix of behavioral questions and another system design challenge. Behavioral questions included:

• My reasons for switching from my previous role.
• Differences I observed between my current and previous companies.
• My experience with ops work and on-call duties.
• A conflict I faced with management and how I resolved it.
• How I keep up with the tech industry, particularly during a career break.
• An interesting tech article I've read, where I cited Discord's blog on indexing trillions of messages.
• My technical growth over the past year.

The system design problem was to design a system to route leads to sales representatives. Key requirements included routing individual leads based on timezone and region, allowing the product team to configure rules, sales reps checking leads via UI or email, and lead scoring, all while handling 15,000 leads per day.

The verdict for this round was "Lean Hire".

Overall, the recruiter provided detailed feedback, indicating that my answers, particularly in the system design and depth expected for an SSE, were lacking. Despite the rejection, the process was smooth, and the feedback was appreciated.