Google PhD New Grad SWE: Trie Screen, License Plates, Android Patterns, and Intervals

Role: Software Engineer, PhD New Grad
Result: Passed the interview loop
Report time: March 2026

The candidate described the questions as random but not especially difficult. The later rounds were virtual rather than in person.

Phone interview: trie

The phone interview used a classic trie problem. The source does not identify whether the required operation was insertion, exact search, prefix search, deletion, autocomplete, or something else, so no exact practice question is linked.

Virtual onsite 1: Nth license plate

A fixed-format license plate contains letters followed by digits. Letters range from A to Z, digits from 0 to 9, and one example format is AAA000.

Order every valid plate lexicographically and return the Nth plate.

Practice: Nth Fixed-Format License Plate

Virtual onsite 2: Android unlock patterns

Count valid Android 3×3 unlock patterns under the standard midpoint rules.

Practice: Android Unlock Pattern Count

Virtual onsite 3: interval intersection

The source names the task as Interval Intersection. A commenter asked whether it was actually intersection or union, but the candidate did not answer.

Practice: Interval List Intersections

Virtual onsite 4

The final round was behavioral and felt more like a conversation than a formal question list.