2024

MindSketch — Real-time Collaborative Diagramming

A real-time collaborative diagramming tool enabling multiple users to draw simultaneously with low-latency WebSocket sync, intuitive canvas UI, and seamless multi-user state accuracy (99%). Deployed on Azure with CI/CD pipelines.

Technology Stack

Next.jsNode.jsWebSocketRedisCanvas APITurborepoTailwind CSSAzure

Overview

Key Challenges

  • Ensuring canvas states remained
  • 99% consistent across clients even with rapid or overlapping strokes.
  • Reducing WebSocket round-trip latency to maintain a smooth real-time drawing experience.
  • Designing a scalable architecture capable of handling spikes in concurrent users.
  • Managing transient cursor movements and stroke data without flooding the network.

Key Learnings

  • Leveraging
  • Redis Pub/Sub dramatically improved event distribution accuracy for real-time WebSocket rooms.
  • State batching + stroke compression reduced bandwidth usage by over 40%.
  • Canvas reconciliation strategies (especially debounced syncing) ensured zero perceived jitter.
  • CI/CD automation with Azure pipelines significantly reduced deployment friction.

Uniqueness

  • Ultra-low-latency collaborative drawing with no flicker or ghost strokes.
  • A fully custom Canvas API-based engine — not whiteboard libraries.
  • Real-time presence indicators with highly optimized WebSocket rooms.

Impact

  • Delivered an experience with <50ms latency for 90% of operations.
  • Achieved 99% multi-user canvas accuracy, measured across 100+ sync events.
  • Improved team collaboration speed by an estimated 20 - 30% in brainstorming sessions.