System design & staff+ interview questions
Feature designs, reliability, multi-brand and SDKs, RFCs, estimation, org bets.
8 sections, 30 questions. Each question has a clear answer, the common traps and likely follow-ups.
- 26.1 · Feature designs
A system design loop asks you to design a product, not a view. The answer is not a diagram of boxes but a sequence of decisions: what the user needs, what must… - 26.2 · Cross-cutting
Every design has the same quiet questions: what happens when a dependency is slow, how many bytes does this screen cost, and what do we measure without harming… - 26.3 · Many apps, many teams
When several apps or teams share code, the design question changes from “does it work” to “can other people use it without breaking each other, and can we… - 26.4 · Staff-plus practice
Above senior level the output is not only code. It is decisions other people can follow, plans that survive contact with reality, a team that recovers well and… - 26.5 · More whole-feature designs
Each classic design question hides one small algorithm that decides whether the answer is right: merging pages without duplicates, choosing a bitrate without… - 26.6 · Collaboration, money and clocks
Three problems where being almost right is wrong: two people editing the same text, money moving exactly once, and deciding which of two writes is newer when… - 26.7 · Estimation and load
Interviewers want to see numbers, and incidents come from numbers nobody did: requests per second, bytes per day, and what ten thousand clients do when a… - 26.8 · More interview designs
Seven more design prompts reported in iOS and mobile loops: limiting request rates, choosing how the client hears about changes, a booking flow with timed seat…