SWE-III at Google

How it went

What they would tell you

How to prepare

Their background

Round by round

1. 1

   Telephonic Round40 min

   The actual interview started with a fairly straightforward statistics question: Given 20 integers, find the mode and median. The approach here was direct sort for the median, and use a hash map for mode. Other problem was Product of the Last K Numbers.

   • Product of the Last K Numbers
2. 2

   Technical Round 160 min

   A grid problem Richest Customer Wealth , it was about working through a matrix and figuring out aggregates, handling row sums.

   • Richest Customer Wealth
3. 3

   Technical Round 260 min

   Given an integer N, count the number of "patterned strings" of length N using only 'A' and 'B'. Such strings must be composed by repeating a substring of length d (where d divides N), so that repeating the substring forms the full string. For N = 4, the answer is 4: {AAAA, BBBB, ABAB, BABA}. My Approach: I initially explained that for each divisor d of N, 2^d strings are possible, but would count duplicates (strings formed by repeating substrings of smaller lengths that divide d). I suggested using a set to filter duplicates. The interviewer wanted a more optimal, non-enumerative solution (without generating duplicates and sets). Time ran out before I could optimize further.

4. 4

   Technical Round 360 min

   The third onsite round involved a more straightforward: Problem: Given a 10 x 10 board and N strips of length 1*x, check if the board is valid. Rules:

   • Strips can be placed horizontally or vertically, but not diagonally.
   • Strips cannot touch each other (either by side or corner).
   • No extra strips should be present on the board apart from those given in the input.
   • I was able to implement a solution and handle all the edge cases. This round went smoothly, and I completed the task within the given time.
5. 5

   Googlyness45 min

   This final interview was about cultural fit handling conflict in teams, owning mistakes, and examples of personal growth. I came in with 4–5 STAR stories prepared in advance, covering scenarios where I'd resolved conflicts or learned from setbacks. The conversation was honest and went smoothly, with natural follow-ups and clarifications.

What came up