YOUR BRIEF
What to work through
Work through a price drop tracker as a spoken system design interview. Start by clarifying the scope, sketch a working design and explain the trade-offs behind your choices.
- View the price history of an Amazon product on the website or in the browser extension
- Subscribe to a price drop alert with a threshold
- Get notified when the price falls below the threshold
- Keep prices current for every tracked product
BEFORE YOU START
Constraints to discuss
- Handle 500 million products
- Price history queries answer in under 500 ms
- Alerts go out within 1 hour of a price change
- Availability over consistency: prices may be briefly stale
Need a starting point?
Watch for these common gaps as you prepare:
- Crawling all 500 million products at the same rate
- Writing extension reports straight into price history
- Scanning every subscription on every price change
- Sending duplicate alerts when the price crosses the threshold back and forth
- Taking the user id from the report body instead of the session
Why this question is in the collection
These sources connect the problem to company interview reports or preparation guides. They do not guarantee what a company will ask you.