The series I am writing now. The full archive of 677 posts lives on the Korean page. as of 2026-08-23
Ep.7Compensation: the order was cancelled but the coupon never came backEp.6Boundaries: we added one order state and stores got overpaidEp.5Isolation: one slow thing stops everythingEp.4Unique IDs: when the clock runs backwardsEp.3DynamoDB: deleted items come backEp.2Rate Limiting: what to block, and where, when traffic floodsEp.1Rate Limiting: six algorithms taken apart, down to the Redis commands
2026-08System Design Ep.6, Boundaries: we added one order state and stores got overpaiddesign
2025-06Event-driven troubleshooting Ep.2: how far can you trust Kafka message processing?debugging
2025-08No passwords to steal: building a plaintext-free server with Passkeyssecurity
2024-06Couchbase CAS concurrency troubleshootingdebugging
2024-04Cutting 500ms: a 7x backend latency storyperformance