LinkedIn Interview Process - Senior Software Engineer

R1 : Phone Screen
The interview started with a few questions about my resume and previous projects.

1: Implement a rate limiter, what algorithms would you use & when.

2: Given a series of opening and closing parenthesis, return if it is a valid sequence or not.

R2 : Coding & Algorithms

1: Given a binary array nums and an integer k, return the maximum number of consecutive 1's in the array if you can flip at most k 0's.

2: Given a binary tree, collect and return its leaves such that we can only remove one layer of leaves in one iteration.

R3 : Coding with AI

The problem involved an adjacency list representing friendships between users. It had 5 parts. Timed out after 3 parts.

1: Find the shortest path between two users, returning the sequence of users traversed from user A to user B.

2: Find the shortest distance between the users.

3: Recommend mutual friends based on no. of connections

R4: Software Design & Architecture

People regularly share third party articles on LinkedIn with others. Design a system to maintain a Top-N leaderboard of the most-shared articles over rolling windows of 5 minutes, 1 hour, and 24 hours. System should be highly scalable and provide accurate responses for any rolling window.

R5: Host Manager

General discussion on couple of past projects, my individual contributions and role, operational excellence, providing guidance and mentorship etc:
Also involved a design question (no HLD diagram expected): We have a pool of hosts provisioned in house, where we have deployed one of our services. We are currently using the same set of hosts to collect and store the logs, metrics. What are the bottlenecks, limitations of doing this, and how would we scale this system?