Start by clarifying the requirements and constraints of the system, then outline a high-level architecture that addresses scalability, and finally dive into specific components and trade-offs. Emphasize how your design can handle growth in users, data, and traffic while maintaining performance and reliability.
Pro tip: Always tie your design decisions back to the specific needs of the product and Apple's ecosystem, such as privacy, seamless integration, and premium user experience. Show that you consider not just technical scalability but also operational and business scalability.
Ask questions to understand the functional and non-functional requirements, such as expected scale, latency, consistency, and availability needs. This ensures your design is tailored to the problem.
Sketch the main components (e.g., clients, load balancers, servers, databases, caches) and how they interact. Focus on the overall architecture before diving into details.
Elaborate on critical parts like data storage (SQL vs NoSQL, sharding, replication), caching strategies, and message queues. Discuss how each component scales horizontally.
Discuss trade-offs between consistency, availability, and partition tolerance (CAP theorem), as well as latency vs throughput, and cost vs performance. Explain your choices.
Recap the design, highlight how it meets the requirements, and mention potential bottlenecks or future improvements. Be open to feedback and iterate if needed.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.