Cracking Roblox's Software Engineer Interview: Mastering the Rate Limiter Challenge

roblox | Software Engineer | Interview Experience

Interview Date: Not specified
Result: Not specified
Difficulty: Not specified

Interview Process

During the tech phone screen, I was asked to implement a rate limiter. The interviewer explained the scenario where we need to limit the number of requests a user can make to an API within a certain period. Initially, I started by discussing the requirements and constraints for the problem. The interviewer was very collaborative and provided useful hints along the way.

I decided to use a token bucket algorithm, which I explained thoroughly to the interviewer. They seemed satisfied with the explanation and allowed me to outline my approach on a whiteboard. I wrote out the structure of my class, the variables I would need, and the methods for adding tokens and checking the rate limit.

After coding the initial version, I walked through the code step by step, discussing its efficiency and potential edge cases. The interview lasted around 30 minutes, and towards the end, I had the opportunity to ask questions about the team and the projects they are working on. Overall, it was a positive experience, albeit a bit challenging!

Technical Questions

  1. Rate Limiter (Design, Rate-Limiting)

Tips & Insights

  • Be prepared to discuss the requirements and constraints of the problem before diving into the solution.
  • Use collaborative approaches and be open to hints from the interviewer.
  • Familiarize yourself with common algorithms like the token bucket for rate limiting.
  • Engage with the interviewer by asking questions about the team and projects.