Google L3 New Grad Loop: Room Allocation and Sliding-Window Rounds

Role: Software Engineer, L3 / New Grad
Result: Passed the interview loop
Report time: June 2026

The candidate completed three main interviews plus one additional round. A comment later clarified that the first and additional rounds were virtual, while the middle two were onsite.

Round 1: DFS / recursion

The candidate first wrote a recursive solution and then discussed another approach. The interviewer was friendly and provided hints.

The candidate later said they no longer remembered the exact prompt or follow-ups, so the task cannot be reconstructed safely.

Round 2: student room allocation OOD

Given student IDs and room IDs, each student prefers either a two-person room or a four-person room. Design a system that assigns rooms according to student preferences.

The discussion focused on class design, data structures, and allocation logic rather than a difficult algorithm.

Practice: Design Student Room Preference Allocation

Round 3: sliding-window frequency tracking

Use a HashMap with a sliding window to maintain element frequencies as the window moves. The source describes the difficulty as LeetCode Medium but does not preserve a more specific output format.

Practice: Sliding-Window Frequency Snapshots

Additional round

The additional interview also used a sliding window and required updating state as the left and right pointers moved. The exact objective and output were not preserved.

Overall experience

The candidate found the interviewers friendly, most questions around LeetCode Medium, and communication and reasoning especially important.