The Scenario
You are the database architect for a new Twitter clone. When a celebrity with 5 million followers posts a new message, those 5 million users need to see it in their timeline immediately. A standard SQL `JOIN` on the followers table is taking 30 seconds to run.
The Brief
Design the schema and architectural strategy for the social feed. You must decide whether to use a Push model (Fan-out on write), a Pull model (Fan-out on read), or a hybrid approach. Explain your database choice (e.g., PostgreSQL, Cassandra, or a Graph DB).
Deliverables
- The schema design for Users, Follows, and Posts
- An architectural diagram or explanation of the "Feed Generation" process (Push vs. Pull)
- A defense of the chosen indexing strategy to make reads as fast as possible
Submission Guidance
There is no single correct answer here. The test is on your ability to articulate the trade-offs of Fan-out on Read versus Fan-out on Write.
Submit Your Work
Your submission is graded against the rubric on the right. If you pass, you get a public Badge URL you can share on LinkedIn. There is no draft save, so work offline first and paste your finished response here.