Part III

Whiteboard questions as interviewers actually ask them, each with a full answer in the shape a 45-minute round rewards: clarifying questions, scope, the box diagram with one job per box, the API, two or three deep dives with their trade-offs, and the follow-ups that come after a good answer. Client-side throughout; no backend sharding.

• ·The shape of the round7 minHow a session runs as a simulated 45-minute interview, what is graded, and how each question chapter is laid out.
• 01Image loading and caching library50 min"Design an image loading library, something like Kingfisher or Nuke."
• 02Infinite photo feed50 min"We have a feed of photos that scrolls forever. Design the client."
• 03Chat client50 min"Design the client side of a chat app."
• 04Offline notes that sync50 min"Design a notes app that works fully offline and syncs."
• 05A grocery catalogue that depends on the address50 min"Design the home and catalogue screens of a 10-minute grocery app, where what's in stock depends on the address."
• 06A cart where stock changes while you shop50 min"Design the cart and checkout for our grocery delivery app. Stock and prices can change while the customer is shopping, and we must never charge twice."
• 07Uploading fifty photos50 min"The user picks 50 photos and uploads them. Design that."
• 08Forty engineers, one app target50 min"We're 40 engineers in one app target. Design the module structure."
• 09The networking layer50 min"How would you structure the networking layer of this app?"
• 10Push notifications, end to end50 min"Design how this app handles push notifications end to end on the client."
• 11Tracking the order to the door50 min"Design the order-tracking screen for a delivery app."
• 12Architect this screen, and tell me why50 min"Here's a spec and a wireframe. Architect this screen, and tell me why."
• 13Adding SwiftUI to a large UIKit app50 min"We have a large UIKit app and we're adding SwiftUI. How do you structure that?"
• 14An analytics SDK for other teams50 min"Design an analytics SDK we'd ship to other teams."
• 15Prices that move several times a second50 min"Design a screen showing live prices that update several times a second."
• 16A video player screen50 min"Design a video player screen for our app."