Interview Experience: Sr. Software Engineer @ Osmos.ai
Summary
I interviewed for a Sr. Software Engineer role at Osmos.ai, navigating through an online assessment, a technical round focusing on LFU cache design, and a system design round covering URL shortener and trending posts. Despite a strong performance, I was ultimately rejected.
Full Experience
I was approached by the HR team regarding the Sr. Software Engineer position at Osmos.ai. Here’s a brief overview of my interview process:
🧮 Online Assessment
My journey started with an Online Assessment. I received the OA link with a 48-hour deadline for a 1.5-hour test, which I completed in about 20 minutes. It consisted of two LeetCode Medium-level coding questions and a few aptitude/DSA conceptual MCQs.
💻 Technical Round (1 hour)
This was primarily a system coding round. I was asked to design an LFU Cache and walk through a dry run. The interviewer was engaging, and I found it to be an enjoyable session. Towards the end, we also discussed topics like database internals and query optimizations.
🏗️ System Design Round (1 hour)
Next, I faced the System Design Round. I was asked to design a URL Shortener. I structured my approach well from the beginning, discussing edge cases, bottlenecks, and optimizations, and managed to complete it within 30 minutes.
Then, the interviewer added a follow-up question: “How would you design Facebook’s Trending Posts section?” I explained my thought process, trade-offs, and scaling considerations, and the discussion went smoothly. Overall, the interviewer seemed quite satisfied with my solutions and reasoning.
🧠 Reflection
I was genuinely excited about the opportunity and gave it my best effort. Even though I felt confident about my performance, I later received an email stating that I didn’t fit their current requirements. It was disappointing — especially after multiple rounds — but I understand it’s part of the journey.
🏢 Company Review (Osmos.ai)
The interviewers were technically sound and discussions were fair and interactive. However, I felt the overall process was inconsistent — communication wasn’t very transparent, and they can ghost or reject candidates abruptly after multiple rounds.
Interview Questions (3)
Design and implement a Least Frequently Used (LFU) cache. The cache should support get(key) and put(key, value) operations. When the cache reaches its capacity and a new item needs to be inserted, the item with the least frequency should be evicted. If there's a tie in frequency, the least recently used among them should be evicted.
Design a scalable URL shortening service. Consider aspects like generating short URLs, mapping them to long URLs, handling collisions, storing mappings, and discussing system components, APIs, database choices, and scalability.
Design the 'Trending Posts' section for a platform like Facebook. This involves considering how to identify trending topics/posts, collect and process data, rank posts, store results, and display them to users. Discuss trade-offs and scaling considerations for high traffic.