Google Early Career Onsite: Opaque Queues and Restaurant Waitlist OOD

Role: Software Engineer, New Grad / Early Career
Result: Passed R2 and entered Team Match
Report time: April 2026
Application: Referral

Timeline

1. Applied in early October 2025.
2. Completed the OA in mid-November.
3. Scheduled R1 five days later and completed R1 in early December.
4. Passed R1 after two days and scheduled R2 for January.
5. Rescheduled the in-person R2 to late February.
6. Learned about Team Match roughly one month later.

The candidate expected difficult algorithms but received two object-oriented-design rounds.

Onsite round 1: smallest opaque queue

There are many queues. Each queue exposes pop() and empty(), but its size cannot be queried. Implement get_min() to identify the queue with the smallest size.

The candidate popped through each queue and used a HashMap to remember its observed size. The source does not clarify whether queues must be restored, exactly what get_min() returns, or whether other queue operations are available, so no practice link is asserted for this task.

Onsite round 2: restaurant waitlist

Design a restaurant waitlist. The reported follow-ups were ordinary scenario changes, such as whether one person could hold multiple reservations, how the model should change, and complexity analysis.

Practice: Restaurant Waitlist

Preparation takeaway

The candidate felt basic optimal solutions and clear communication were the most important requirements. They also found system-design preparation useful for open-ended follow-ups about scalability, concurrency, and how a waitlist might evolve into a queue- or Kafka-style system, while noting that those broader ideas were discussion rather than judged requirements.