Google - Mid/Senior Frontend Engineer - Onsite Loop Technicals

Level: L4/L5 (Mid/Senior Frontend Engineer equivalent)
Education: Bachelor’s Degree
Years of Experience (YOE): 6
Questions Asked:

  • Technical Phone Screen: Core JavaScript problem involving manipulating data structures efficiently, possibly related to DOM structure or event handling logic optimization. (e.g., Optimize a function processing nested data representing UI elements).

  • Onsite Coding 1 (Algo/DS Focus): Algorithm question, often graph or tree-based, framed in a frontend context. (e.g., Given a component tree, find the optimal rendering path or detect circular dependencies). Required Big O analysis.

  • Onsite Coding 2 (Practical Frontend): Implement a complex UI component from scratch or debug an existing one. (e.g., Build a typeahead/autocomplete search input, handling asynchronous requests, debouncing, UI state updates, basic accessibility). Focus on clean code, edge cases.

  • Frontend System Design: Architect a significant frontend application feature. (e.g., Design the frontend for a real-time collaborative document editor or a highly interactive data visualization dashboard). Discussion included component breakdown, state management strategy (at scale), API contract design, performance bottlenecks (rendering, network), caching layers, and potential tradeoffs.