← Back to Directory

Whatnot interview notes, page 4 of 4

Mid-sized

Most of these Whatnot write-ups come from Software Engineers (25), then Machine Learning Engineers (3) and Mobile Engineers (3). The most reported rounds are the technical phone screen (20), the system design round (7), the product sense round (3) and the hiring manager screen (1).

32 interview notes · updated Sep 2026

Whatnot·Machine Learning Engineer·Onsite - System Design / Architecture

Jul 2026
Whatnot MLE interview focused on designing a full trending livestream recommendation system, which sounds scoped until you realize they want you to cover everything from feature collection to failure handling. The follow-up about stream liveness caught me a little flat-footed.
  • Design an end-to-end ML system for surfacing trending livestreams to users on a live-commerce platform. A scoring model already exists as a service. Walk through product goals, success metrics, feature collection, candidate generation, ranking, architecture, and scaling.
  • How would you prevent stale, ended, low-quality, or spammy streams from appearing in the trending feed?
  • Follow-up: How do you guarantee that a stream shown in the trending feed is actually still live at the moment a user sees it?
  • How would you approach experimentation and monitoring for this trending feed system?

“This is a beast of a question and I think I spent too long on the feature collection part early on, which left me rushing through the online/offline architecture at the end.”

View Post

Whatnot·Software Engineer·Technical Phone Screen

Jul 2026
Coding interview at Whatnot for a Software Engineer role. The task was building a functional Tic-Tac-Toe app in 45 minutes, which sounds trivial until you're actually in it trying to keep state clean and not embarrass yourself.
  • Build a working Tic-Tac-Toe mobile app within 45 minutes. It needs a 3x3 grid, two local players alternating turns, win and draw detection, move prevention after the game ends, a status display, and a reset button.

“The scope felt manageable at first but the win detection logic is where I started second-guessing myself.”

View Post