System designMediumsd-g078

Subject RecommendationLevel Mid–Senior~45 minCommon in ML systems · Algorithms & data structures interviewsIndustries Technology

Question

Design a 'People You May Know' / connection-recommendation system for a 700M-user professional network. Suggest relevant people to connect with based on shared connections, company, school, and interactions. Constraints: refresh suggestions daily, must work for brand-new users with few connections, and avoid suggesting people the user explicitly dismissed.

What a strong answer looks like

Clarify scale and constraints first. Propose a clean component breakdown, then go deep on the hard parts — data model, bottlenecks, consistency, failure modes — and name the trade-offs you are making.

Learn the concepts

Narrate your design

Loading whiteboard…

Run or narrate your approach, then ask the coach.