Google PhD New Grad Five-Round Loop: Time-Series Sum, Mahjong, and Team Match

Role: Software Engineer, PhD New Grad
Result: Passed the loop and entered Team Match
Report time: April 2025
Application: Referral

Timeline

• September 2024: applied with a referral
• October: completed hiring assessment and recruiter outreach
• Mid-November: phone screen
• February 2025: virtual onsite scheduled after a long wait
• March: four-round virtual onsite
• April: one additional coding interview
• One week later: entered Team Match

Across the phone screen, onsite, and additional round, the candidate completed five coding interviews.

Recoverable coding 1: piecewise-constant time-series sum

Two arrays contain (time, value) pairs. Each value remains active until the next timestamp. Return the summed signal in the same format.

Example:

• t1 = [(0,0),(2,1),(8,0)]
• t2 = [(0,0),(1,3),(5,2)]
• Result: [(0,0),(1,3),(2,4),(5,3),(8,2)]

Practice: Sum Two Piecewise-Constant Time Series

Recoverable coding 2: simplified Mahjong

Given 14 values from 1 through 9, determine whether the hand contains one pair plus four three-tile groups. A group may be a consecutive run from 123 through 789, or three equal tiles. Wraparound runs such as 891 are invalid.

Practice: Validate a Simplified Mahjong Winning Hand

Other coding rounds

The remaining source labels were a simplified Range Module with insert(lower, upper) and query(num), a salesman maximum-profit task, and an arithmetic-progression variation. Their encoded references or complete output contracts were not retained, so they are not linked as exact questions.

Behavioral interview

Questions covered using another person's perspective, challenging the status quo, responding when a new approach fails, meeting a tight deadline, and prioritizing multiple tasks.