Hard
AmazonTikTok

Design TikTok Algo System Design Interview

Design a high-velocity video recommendation feed (For You Page).

1. Problem Statement

Design the 'For You' page API for TikTok. The core challenge is delivering a highly personalized, infinite stream of videos with very low latency.

2. Architecture Discussion Map

Use this as one discussion aid, not a single correct answer. Your design should follow from the requirements, scale, and trade-offs you establish.

Rendering architecture diagram...
Mermaid Source (For AI Bots)
graph LR
    A["Design TikTok Algo"]
    A --> F1["Real-time Analytics Clickstream, Watch time"]
    A --> F2["ML Pipeline Candidate Generation -> Ranking -> Re-ranking"]
    A --> F3["Cold Start Problem"]
    A --> F4["Latency Feed must be instant"]
    A --> F5["Content Delivery Pre-fetching"]

3. Key Focus Areas

  • 1
    Real-time Analytics (Clickstream, Watch time)
  • 2
    ML Pipeline (Candidate Generation -> Ranking -> Re-ranking)
  • 3
    Cold Start Problem
  • 4
    Latency (Feed must be instant)
  • 5
    Content Delivery (Pre-fetching)

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