Google Phone Screen L4

My honest reflection:
Just wanted to share my recent experience with Google’s phone interview, in case it helps anyone else who’s preparing or feeling unsure afterward.

The problem:

Given a 2D array of word sequences (each sub-array is a phrase), build a function that takes a word as input and returns the most frequent word that immediately follows it across the dataset.
The interviewer said that the only thing we worry about is a fast lookups (because dataset could be huge).
If the input word doesn't exist in the dataset or is never followed by another word, return an empty string "".

I can't find straight LeetCode clone, but here is the similar ones:
https://leetcode.com/problems/top-k-frequent-words/description/
https://leetcode.com/problems/word-frequency/description/

What I did:

• Asked a few questions
• Understood the problem and explained my plan clearly
• Suggested preprocessing the data into a frequency map for constant-time lookups
• Started implementing, but didn’t finish the full working code in time (I’d say I completed about 60–70% of the solution)
• I also discussed how we could extend the design in the future to support returning the top 2, 3, or more most frequent next words, not just the top one — to make the solution more flexible and scalable.

Unfortunately, the initial discussion and verbal explanation took up a lot of time — around 25-30 minutes — and I honestly didn’t realize how much time had passed. That was a mistake on my part. While it’s good advice to talk through your approach before coding, I’d caution others: don’t overdo it like I did.

What happened after:

A few days later, I got a call from the recruiter.
They told me:
“The round didn’t go as expected, but we’d like to give you one more phone round.”

My own takeaways:

Track you time during interview
Communicating clearly and staying calm is still important and valued