...Real-world examples examine how major services scale storage, messaging, streaming, payments, collaboration, and other workloads. Fundamental topics include APIs, caching, consistency, databases, DNS, Docker, Kafka, Kubernetes, load balancing, microservices, and service discovery. Separate guides cover interview frameworks and design exercises for products such as ChatGPT, Spotify, WhatsApp, and YouTube. The repository also collects AI agent concepts and selected software architecture white papers.