Design a Neighborhood Newsfeed System
Company: Nextdoor
Role: Software Engineer
Category: System Design
Difficulty: medium
Interview Round: Technical Screen
Design a neighborhood-based social newsfeed system similar to Nextdoor.
Users belong to neighborhoods and can see posts from neighbors, local groups, public agencies, and nearby relevant communities. The feed should support text posts, photos, videos, comments, reactions, ranking, privacy boundaries, and near-real-time updates.
Discuss:
- Functional requirements
- Non-functional requirements
- Core APIs
- Data model
- High-level architecture
- Feed generation and ranking strategy
- Privacy and neighborhood access control
- Storage, caching, and scalability
- Reliability, observability, and trade-offs
Quick Answer: This question evaluates the candidate's ability to design a neighborhood-centric social newsfeed, testing competencies in scalable distributed architecture, data modeling, API design, feed generation and ranking, privacy and access control, and near-real-time data propagation.