Design Mobile Model Usage Quotas
Company: OpenAI
Role: Android Engineer
Category: System Design
Difficulty: medium
Interview Round: Technical Screen
Design the mobile and backend API flow for controlling access limits to different AI model versions in a ChatGPT-like mobile app.
Requirements:
- The product offers multiple model versions, and each model may have a different free usage quota.
- The mobile app must know whether the current user can access a selected model.
- If the user exceeds the free quota, the app should show a toast explaining how long remains until the next free access becomes available.
- The toast should also provide a link or call-to-action that lets the user upgrade to a paid plan.
- Provide backend endpoint designs.
- Provide a mobile-side architecture using MVI or MVVM.
- Provide representative function signatures for the mobile client and backend contract.
- Assume the mobile implementation is Android-focused, but the API should be platform-independent.
Quick Answer: This question evaluates system design and API design skills focused on quota and access control for multiple AI model versions, plus mobile architecture knowledge (Android MVI/MVVM), authentication/authorization, and client-server contract clarity.