HARDSearch & Discoverystaff engineer

Design Google Maps

Design a mapping and navigation service like Google Maps with features like map rendering, directions, and real-time traffic.

Estimated Time: 60 minutes
#maps#routing#geospatial#graph-algorithms#traffic
Solution Overview

Use hierarchical tile-based rendering, graph algorithms for routing, and crowdsourced data for real-time traffic.

Hints to Get Started
1

How would you structure the road network graph?

2

Think about map tile caching strategies

3

Consider real-time traffic data ingestion

Requirements

functional

  • Map display
  • Search places
  • Directions
  • Real-time traffic
  • Street view
  • Offline maps

non functional

  • Fast map loading
  • Accurate ETA
  • Global coverage
  • Low bandwidth usage
Routing

graph

edges

Road segments with weights (distance, time, traffic)

nodes

Intersections

algorithm

Modified A* or Contraction Hierarchies

optimizations

  • Precomputed shortcuts
  • Hierarchical decomposition
  • Bidirectional search
Traffic

prediction

ML models combining current + historical

processing

Real-time stream processing with Kafka + Flink

data sources

  • GPS from mobile apps
  • Road sensors
  • Historical patterns
Deep Dives

offline

Download region tiles + routing graph subset

eta accuracy

Segment-level traffic prediction, consider turns

places search

Geospatial index + text search hybrid

Map Rendering

tile system

levels

22 zoom levels, each 4x previous tiles

delivery

CDN with aggressive caching

description

Pre-rendered tiles at multiple zoom levels

vector tiles

pros

  • Smaller size
  • Dynamic styling
  • Smooth zoom

description

Send raw data, render on client