You have 90 seconds to verbally explain how you would design a distributed unique ID generator like Twitter Snowflake.
Your system should: - Generate globally unique 64-bit IDs - Support 10,000+ ID generations per second per node - IDs should be roughly sortable by time - Work across multiple data centers - No coordination between nodes required
Explain your ID structure, generation algorithm, and handling of clock skew.
How to approach it
- Hint 1
Compose the 64-bit ID from multiple parts: timestamp, worker/node ID, and sequence number
- Hint 2
Use system time in milliseconds for the timestamp portion to ensure time-ordering
- Hint 3
Handle clock drift by waiting if clock moves backward
Ready to answer it out loud?
Record your answer in 1:30 and Preptile scores it 1–10 with specifics — what landed, what you skipped, and what to say next time.
Practising needs an invite code. Join the waitlist and we’ll send you one.