The interview started with basic DSA questions. The interviewer first asked the classic “Add Two Numbers using Linked List” problem from LeetCode. I explained the approach using carry handling and traversing both linked lists simultaneously. They also discussed general linked list concepts like traversal and node manipulation. Then the discussion moved to system design. The interviewer asked me to explain the high-level system design of Instagram, including components like: * user feed generation * database storage * caching * load balancing * media storage * scalability handling for millions of users After that, they asked some computer architecture concepts related to the Apple M1 chip, specifically about: * L1 cache * L2 cache * L3 cache The discussion was around: * cache hierarchy * speed differences * why smaller caches are faster * how CPUs use caches to reduce memory access time Overall, the interview focused on: * DSA fundamentals * linked lists * system design basics * computer architecture concepts The difficulty level was moderate, with more focus on conceptual understanding and explanation ability rather than only coding.

A brief self-introduction followed by coding problems. The coding problems are to develop APIs using any language you prefer. The interviewer was nice and shared useful info about the position.