Postgresql

Prerequisite: Part 4 of the System Design Masterclass. Read Part 3: Caching Strategies to understand the cache layer before examining storage. Answer-first: Database sharding distributes data horizontally across independent partitions (shards) based on a shard key, reducing write contention and enabling linear storage growth. Choosing the wrong shard key leads to hot spots that can be worse than no sharding at all. Vertical vs Horizontal Scaling — When to Switch? Answer-first: Vertical scaling (scale-up) increases resources on a single server — simple but has a hard physical ceiling and non-linear cost growth. Horizontal scaling (scale-out) adds more servers — no theoretical ceiling, linear cost, but significantly higher operational complexity. ...

What Is Real-Time Inventory Synchronization? Real-time inventory synchronization is the process of propagating stock count changes from the system of record (database) to all sales channels — web storefront, mobile app, WMS, ERP — in sub-second time. Instead of batch ETL jobs that run every hour, a CDC + Kafka pipeline streams every committed stock change as an event, eliminating overselling and stale stock displays. Handling this during a flash sale — where thousands of users attempt to purchase a highly contested SKU simultaneously — is a pinnacle architectural challenge. Traditional synchronous database updates collapse under lock contention. ...

Answer-first: Build an autonomous AI pipeline that scrapes and publishes expat rental intelligence for Vietnam, turning articles into a B2B lead funnel. Most AI content projects are built around one question: how do I publish more? LeaseInVietnam is built around a different question: how do I make every published piece convert? The system is an autonomous relocation hub targeting expats and digital nomads renting in Southern Vietnam — Ho Chi Minh City, Nha Trang, Phú Quốc. It produces content in American English, publishes daily via GitOps, and routes every reader interaction toward a B2B lead funnel that pays commission on moving services, cleaning bookings, furniture rentals, and legal consultations. ...