Back to practice
FE System DesignAdvanced55 minutes

Collaborative Whiteboard

Design a real-time collaborative whiteboard with CRDTs, presence, undo/redo, and large-session performance.

LLM-friendly summary

An advanced collaborative frontend system design challenge about CRDTs, presence, large canvases, and multi-user consistency.

Scenario

A collaborative canvas product must support multiple simultaneous editors, smooth local interactions, and safe sync under packet loss.

What you need to design

  1. 1Choose a collaboration model such as CRDTs or OT.
  2. 2Handle cursor presence and latency masking.
  3. 3Support undo and redo in a multi-user environment.
  4. 4Keep rendering smooth on large boards.
  5. 5Plan for observability and failure recovery.

Concepts

CRDTsPresenceUndo/RedoLatency Masking

Skills

Collaborative SystemsCanvas PerformanceState Synchronization

What good solutions are evaluated on

  • - Collaboration protocol and merge strategy
  • - Performance and rendering quality
  • - Presence and interaction design
  • - Recovery and consistency trade-offs

Ready to practice this yourself?

Open the interactive AlgoReason workspace to sketch the architecture, write notes, and submit for AI evaluation.

Practice this problem