System Design AI

Guided practice

Start with a template. Work through each step. Ask Coach when you need a second opinion.

Classic designs 3

Ordered by design number

Company tags are community-reported. Counts on cards show how many people reported that design.

Change data captureClear filters

39. Design a Calendar System
Google Calendar-style events with recurrence, RSVPs and on-time reminders, using CDC for change notifications and a delay queue for reminders.
ClassicMedium
Caching Queues Databases
+5
Calendar Change data capture Notifications PostgreSQL Scheduling
Worked design
Practice
51. Design a Local Delivery Service like Gopuff
Show what 10,000 small warehouses can deliver within the hour in under 100 ms, and take multi-item orders without ever selling a unit twice.
ClassicMedium
Caching Transactions Aurora
+4
AWS Change data capture Geospatial Inventory
Worked design
Practice
56. Design a Local Business Review Site like Yelp
Search 10 million businesses by place, words and category, keep every average rating exact, and keep fake reviews out.
ClassicMedium
Databases Search AWS
+5
Change data capture Geospatial OpenSearch PostgreSQL Reviews
Worked design
Practice

Self-paced by default. Your answers and canvas stay private. AI feedback runs only when you ask for it.