Meta · System design 1 of 1

How would you design a social news feed?

Feed generation, ranking boundaries, fan-out trade-offs, caching, and product constraints.

Practice question: an editorial practice prompt, not a claim that Meta asks this exact question. Interviews vary by role, level, team, and location.

How to approach this question

A focused three-stage walkthrough

  1. 1
    Scope

    Clarify scale, freshness, ranking, and privacy.

  2. 2
    Design

    Define write, fan-out, storage, ranking, and read paths.

  3. 3
    Stress-test

    Compare fan-out-on-write and fan-out-on-read for different users.

System design framework

Make every architecture choice traceable

Scope

Clarify users, core operations, scale, latency, consistency, retention, and what is explicitly out of scope.

Design

Define APIs and data models, then connect components through the critical read and write paths.

Stress-test

Identify bottlenecks, failures, security concerns, and the trade-offs behind your scaling choices.

Self-review rubric

What a strong practice attempt includes

  • Requirements drive the architecture
  • APIs and data ownership are explicit
  • Scale and failure modes are addressed
  • Trade-offs are explained instead of hidden
Likely follow-ups

Answer the main question first, then take these on one at a time:

  • How do celebrity accounts change the design?
  • Where does ranking happen?
  • How is privacy enforced?
Avoid these mistakes

Check your recording or written solution against this list:

  • Ignoring privacy
  • One fan-out strategy for everyone
  • No degraded mode
Sources and methodology

This guide combines general interview-practice patterns with the public hiring material below. The practice prompt and coaching are PiriPiri AI editorial content, not official Meta questions or answers.

Meta Careers: software engineering full-loop prep ↗
Official sources reviewed 20 September 2026.