Make Duplicate Requests Harmless With Idempotency Keys
A timeout can hide a successful request. Idempotency keys let a backend recognize retries, but the database and external side effects need a coherent design.
Database Design
Databases Behind the Screen: Building Faster, Safer Web Applications
Databases are the foundation of most modern web applications, storing the information that powers user accounts, content, transactions, and analytics. Understanding how to design, query, secure, and scale them is essential for effective web development.