Design an Instagram-like auction platform
Company: Meta
Role: Software Engineer
Category: System Design
Difficulty: medium
Interview Round: Technical Screen
Design an Instagram-like platform that supports **auction posts**.
Users can:
- Create an auction post with photos/video, description, category/tags.
- Set auction rules: start time, end time, starting price, minimum increment, optional reserve price, optional “buy now”.
- Place bids during the auction.
- See real-time bid updates on the auction page.
- Follow creators, like/comment/share, and view a feed.
- Receive notifications (outbid, auction ending soon, won/lost, payment/shipping updates).
Design for a large scale (tens of millions of DAU). Focus especially on:
- Correctness and fairness of bidding
- Handling high bid volume on popular auctions
- Real-time updates and notifications
- Data model and consistency choices
State assumptions, APIs, storage, key services, and the main read/write flows.
Quick Answer: This question evaluates expertise in large-scale system design, including distributed systems, data modeling, real-time messaging, consistency models, and correctness and fairness of auction semantics.