I started with the Activity lifecycle and kind of just...
Start with a high-level overview of the Android architecture, then drill down into the key components and their interactions, using a concrete example like launching an app. Emphasize the layered design and how it enables performance, security, and flexibility.
Pro tip: Mention the Zygote process and how it speeds up app startup by forking, and discuss the role of the Binder IPC mechanism—these details show deep understanding and are often overlooked.
Describe the layered stack: Linux kernel, HAL, native libraries, Android Runtime, and applications. Explain how each layer abstracts the one below.
Walk through what happens when a user taps an app icon: from Launcher intent to ActivityManagerService, Zygote forking, and ActivityThread main.
Explain the four main components (Activities, Services, Broadcast Receivers, Content Providers) and how they communicate via Binder IPC.
Discuss ART (Android Runtime) and how it executes DEX bytecode, including AOT and JIT compilation, and garbage collection.
Cover key system services (e.g., WindowManager, PackageManager) and how the main thread's Looper/Handler processes events to keep the UI responsive.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.
Vague prompt, which I did not handle well.
Start by clarifying the requirements and constraints of the system, then propose a high-level architecture that addresses scalability, availability, and consistency. Iterate on the design by diving into key components and trade-offs, and finally summarize how the design meets the requirements.
Pro tip: Always discuss trade-offs explicitly—Google values engineers who understand that there's no perfect solution, only appropriate ones for given constraints. Also, proactively mention monitoring, alerting, and failure recovery to show production maturity.
Ask questions to understand functional and non-functional requirements, such as expected scale, latency, consistency, and availability needs.
Sketch the main components (e.g., load balancers, services, databases, caches) and how they interact, focusing on data flow and API contracts.
Elaborate on critical parts like data storage (SQL vs NoSQL), sharding, replication, and caching strategies, explaining your choices.
Discuss how the system scales horizontally, handles failures, and ensures data consistency and durability.
Recap the design, highlight trade-offs made, and suggest potential improvements or alternatives.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.