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Google interview notes, page 3 of 215

FAANG / Big Tech

Most of these Google write-ups come from Software Engineers (1,167), then Product Managers (686) and Data Scientists (125). The most reported rounds are the product sense round (667), the technical phone screen (660), the behavioral / leadership round (252) and the onsite coding round (214).

2146 interview notes · updated Oct 2026

Google·Software Engineer·Onsite - System Design / Architecture

Apr 2026
Google system design round for a software engineer role, focused entirely on building a fraud detection ML system. Pretty deep dive, covered everything from feature engineering to serving infrastructure. Walked out unsure if I'd gone broad enough or just spread myself too thin.
  • Design an end-to-end fraud detection machine learning system for financial transactions.
  • How would you handle the severe class imbalance between fraudulent and legitimate transactions in your model?
  • Fraud labels often arrive days later via chargebacks. How does that affect your training pipeline and what do you do about it?
  • How would you serve fraud predictions at low latency in a production environment, and how would you test changes safely?
  • A new user or merchant has no transaction history. How does your system handle fraud detection for them?

“I started with problem framing which felt right, binary classification on transactions with extreme class imbalance.”

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Google·Software Engineer·Technical Phone Screen

Apr 2026
Google frontend engineer interview, got asked a classic CS fundamentals question. Nothing too wild but it's Google so you know they want you to be precise about it.
  • Can you explain how binary search works?

“Felt like a warmup but I still fumbled the off-by-one explanation.”

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Google·Software Engineer·Technical Phone Screen

Apr 2026
Google SWE interview with a tree problem that looked like a BST question but wasn't. The invariants were broken so you couldn't trust the structure, which I think was the whole point.
  • You're given a ternary tree where each node can have up to three children (left, middle, right), originally built with BST-like ordering rules. But the tree may be corrupted and some nodes violate those rules. Find the mode of all node values in the tree.

“My first instinct was to try to exploit the BST property and do something clever with the ordering, which was a mistake because the whole premise is that the invariants are broken.”

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Google·Software Engineer·Onsite - Behavioral / Leadership

Apr 2026
Interviewed for a SWE role at Google and got hit with a behavioral question about owning a mistake. Pretty standard stuff but I fumbled it more than I expected.
  • Tell me about a time you made a mistake.

“I had an example ready but the way I told it felt too polished, like I was reciting something.”

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Google·Software Engineer·Technical Phone Screen

Apr 2026
Google SWE coding round with a string manipulation problem that looked deceptively straightforward. The checksum-based encoding angle threw me off a bit.
  • Given a string, a validation string, and a chunk length k, split the input string into substrings of length k. For each chunk, compute a checksum by summing the character values, then use that checksum (mod the length of the validation string) as an index into the validation string to pick a character. Return the string formed by concatenating all the picked characters in order.

“I started coding before I fully thought through the modulo indexing part and had to backtrack, which felt bad.”

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Google·Product Manager·Onsite - Product Sense / Strategy

Apr 2026
PM interview at Google with a classic estimation question. Nothing too wild but it requires more structure than you'd think going in.
  • Estimate the number of people who use Google Search to find a new job.

“I started with total internet users and tried to segment down by job-seeking behavior, which felt reasonable, but I got tangled up trying to define 'actively looking' vs 'passively browsing.' Ended up just picking a number for job-seeker rate without really defending it.”

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Google·Software Engineer·Onsite - System Design / Architecture

Apr 2026
Google system design screen for a System Development Engineer role. One big infrastructure question that sprawled into like five different topics. Felt like I was holding on for dear life by the end.
  • You have one server with one public IP and need to host three separate business websites, each on its own domain. Walk through how you'd make that work, covering DNS, virtual hosting, HTTPS with per-domain certificates, reverse proxying, and the trade-offs between port-based and name-based approaches.

“This question sounds almost too simple until you actually try to explain all the moving parts in sequence.”

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Google·Software Engineer·Technical Phone Screen

Apr 2026
Google interview question about routing algorithms for Maps. Not much context on how the full loop went but this particular question stuck with me.
  • How would you decide between two routing algorithms for Google Maps?

“This is the kind of question that sounds like a pure algorithms problem but really isn't.”

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Google·Software Engineer·Recruiter / HR Screen

Apr 2026
Interviewed for a bizops role at Google, and it was pretty much what you'd expect from a big tech screen.
  • What drew you to a career in technology?

“Pretty standard opener but I still fumbled it a bit.”

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Google·Technical Program Manager·Technical Phone Screen

Apr 2026
Interviewed for a TPM role at Google and got hit with a classic infrastructure-meets-product question about how Maps calculates ETAs. Not a lot of context to go on, but it's the kind of question that sounds deceptively simple until you actually try to answer it.
  • How does Google Maps compute estimated time of arrival (ETA)?

“I started with the obvious stuff, road graph, historical traffic, real-time data, but then kind of stalled when thinking about how all those signals actually get weighted and combined.”

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