System Design AI

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Classic designs 4

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5. Design a Chat System
Send durable messages, reconnect devices and explain ordering and delivery receipts.
ClassicMedium
Databases Security Privacy
+11
Distributed systems AWS Chat DynamoDB End to end encryption Messaging Multi region Offline first Ordering Redis Pub/Sub WebSockets
Worked design
Practice
7. Design a File Storage Service
Upload and share large files with resumable transfer, versions and safe metadata changes.
ClassicMedium
Databases Object storage Security
+9
AWS Deduplication DynamoDB File sync Large files Multipart upload Permissions Versioning WebSockets
Worked design
Practice
47. Design an Online Judge like LeetCode
Run strangers' code safely in single-use microVMs, return verdicts within 5 seconds, and rank 100,000 contestants live.
ClassicMedium
Caching Queues Databases
+8
Security AWS Firecracker Leaderboards Online judge Redis Sandboxing Amazon SQS
Worked design
Practice
99. Design a Cross-Product Tagging System
One set of tags across Jira issues, Confluence pages and Bitbucket pull requests: batch renders, tag pages that never leak, suggestions, popular tags.
ClassicMedium
Databases Search Security
+6
AWS Collaboration DynamoDB Many to many OpenSearch Permissions
Worked design
Practice

Each design brings together the brief, practice, examples and discussion.