System Design AI

Guided practice

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

All designs 4

Ordered by design number

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

TransactionsClear filters

Practice briefStart with your own approach
14. Sell a limited drop without overselling
Separate reservation, payment and confirmed purchase during a 50,000-person launch.
Product & backendMedium
Concurrency Transactions Idempotency
+2
Inventory Payments
Discuss
Practice
30. Transactional Outbox
A service commits to its database and then publishes an event. If it dies in between, the row exists and no one hears about it. Publishing first has the mirror problem: an event for a write that never happened. There is no ordering of two independent systems that makes this safe.
Product & backendMedium
Queues Streaming Transactions
+5
Distributed systems Change data capture Consistency Kafka Outbox
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
85. Design a Change Data Capture Pipeline
Every committed change in Aurora and DynamoDB, read from the log and delivered in order per row to search, caches, Redshift and an S3 lake.
ClassicMedium
Queues Databases Streaming
+8
Transactions Distributed systems AWS Change data capture Debezium Kafka Outbox PostgreSQL
Worked design
Practice

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