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982 interviews, 422 offers, and prep resources from 102 companies

Interview Experience

Roblox · Software Engineer

I was asked to write code that parses a stack trace log and uses a stack to count call occurrences. I also needed to parse call and return statements. The coding problem was: You’re given a sequence of logs representing function entries and exits in a single-threaded program. Each entry is of the form `"-> funcName"` and each exit is `"<- funcName"`. When a function is entered, the current full call path is the `->`-joined list of functions on the stack (top included). For example, if the current call stack is `[main, handleEvents, handleClickEvent]`, the path is: ``` main->handleEvents->handleClickEvent ``` Your task is to count how many times each full call path occurs (on every `->` event) and return the path with the highest frequency. 🧠 Tie-Breaking Rules If multiple paths share the same highest frequency: 1. Prefer the deeper path (one with more functions). 2. If depth is also tied, prefer the one that appeared first while scanning the logs (left-to-right). If the input is empty, return an empty string. 📘 Example 1 Input ``` ["-> main", "-> handleEvents", "-> handleClickEvent", "<- handleClickEvent", "-> handleClickEvent", "<- handleClickEvent", "<- handleEvents", "<- main"] ``` Counting (on each entry): - `main` → 1 - `main->handleEvents` → 1 - `main->handleEvents->handleClickEvent` → 2 Output ``` "main->handleEvents->handleClickEvent" ``` 📘 Example 2 Input ``` ["-> main", "-> handleEvents", "-> handleKeyEvent", "<- handleKeyEvent", "-> handleClickEvent", "<- handleClickEvent", "-> handleClickEvent", "<- handleClickEvent", "-> handleKeyEvent", "<- handleKeyEvent", "<- handleEvents", "<- main"] ``` Here both `main->handleEvents->handleClickEvent` and `main->handleEvents->handleKeyEvent` occur twice. We choose the click path because it reached the top frequency first. Output ``` "main->handleEvents->handleClickEvent" ``` 📘 Example 3 Input ``` [] ``` Output ``` "" ``` ⚙️ Constraints - `0 ≤ len(traces) ≤ 100,000` - Each log line starts with either `"-> "` or `"<- "`. - `funcName` contains only letters, digits, or underscores. - Logs are well-formed — every exit matches a previous entry. - No recursive calls (the same function will not be re-entered before it returns). - The call depth will not exceed 1,000. - Total distinct paths ≤ total entries.

Offer Data Point

ByteDance · AI Research Scientist

Sr.Staff-Level · PhD · San Francisco Bay Area

Base range: $1.21M - $1.47M · bonus · equity · sign-on

System Design

Design Dropbox

Dropbox is a cloud storage and collaboration platform that lets users store, sync, and share files across devices. It is commonly used by individuals and teams to organize documents, collaborate on projects, and securely access files from anywhere. Over time, Dropbox has expanded beyond file storage into productivity tools like document workflows, e-signatures, and team collaboration features.

Coding Question Bank

Coinbase · Group Chat Messages by Room

A messaging platform records chat activity from different users across multiple chat rooms. Each log entry is a colon-separated string in the format ":::" where: userId and roomId are alphanumeric strings timestamp is an integer representing the message time in seconds message is the chat content --- Your task is to process an array of these entries and group them by roomId. Return a JSON-like map where: each key is a distinct roomId each value is the list of original log entries for that room each room’s list is sorted by increasing timestamp ---

Fresh interview reports from the community

Roblox

Software Engineer

CodingPhone ScreenSenior-Level

I was asked to write code that parses a stack trace log and uses a stack to count call occurrences. I also needed to parse call and return statements. The coding problem was: You’re given a sequence of logs representing function entries and exits in a single-threaded program. Each entry is of the form `"-> funcName"` and each exit is `"<- funcName"`. When a function is entered, the current full call path is the `->`-joined list of functions on the stack (top included). For example, if the current call stack is `[main, handleEvents, handleClickEvent]`, the path is: ``` main->handleEvents->handleClickEvent ``` Your task is to count how many times each full call path occurs (on every `->` event) and return the path with the highest frequency. 🧠 Tie-Breaking Rules If multiple paths share the same highest frequency: 1. Prefer the deeper path (one with more functions). 2. If depth is also tied, prefer the one that appeared first while scanning the logs (left-to-right). If the input is empty, return an empty string. 📘 Example 1 Input ``` ["-> main", "-> handleEvents", "-> handleClickEvent", "<- handleClickEvent", "-> handleClickEvent", "<- handleClickEvent", "<- handleEvents", "<- main"] ``` Counting (on each entry): - `main` → 1 - `main->handleEvents` → 1 - `main->handleEvents->handleClickEvent` → 2 Output ``` "main->handleEvents->handleClickEvent" ``` 📘 Example 2 Input ``` ["-> main", "-> handleEvents", "-> handleKeyEvent", "<- handleKeyEvent", "-> handleClickEvent", "<- handleClickEvent", "-> handleClickEvent", "<- handleClickEvent", "-> handleKeyEvent", "<- handleKeyEvent", "<- handleEvents", "<- main"] ``` Here both `main->handleEvents->handleClickEvent` and `main->handleEvents->handleKeyEvent` occur twice. We choose the click path because it reached the top frequency first. Output ``` "main->handleEvents->handleClickEvent" ``` 📘 Example 3 Input ``` [] ``` Output ``` "" ``` ⚙️ Constraints - `0 ≤ len(traces) ≤ 100,000` - Each log line starts with either `"-> "` or `"<- "`. - `funcName` contains only letters, digits, or underscores. - Logs are well-formed — every exit matches a previous entry. - No recursive calls (the same function will not be re-entered before it returns). - The call depth will not exceed 1,000. - Total distinct paths ≤ total entries.

Recent compensation datapoints with context

ByteDance

AI Research Scientist

Date

May. 2026

Level

Sr.Staff

Degree

PhD

System design articles for real interview decisions

Design Dropbox

Handling Large Blobs

Coding questions collected from real interviews

Group Chat Messages by Room

StringHash MapSorting

A messaging platform records chat activity from different users across multiple chat rooms. Each log entry is a colon-separated string in the format ":::" where: userId and roomId are alphanumeric strings timestamp is an integer representing the message time in seconds message is the chat content --- Your task is to process an array of these entries and group them by roomId. Return a JSON-like map where: each key is a distinct roomId each value is the list of original log entries for that room each room’s list is sorted by increasing timestamp ---

Rippling

Software Engineer

Multiple TypesOnsiteMid-Level

I had a phone screen followed by three virtual onsite rounds. (Phone Screen): I chose the AI coding option. The was the logger problem (seen this shared in this site before) Part 1 required implementing the following functionalities, with each function printing the logger after operation: * Removes all occurrences of a configured string before printing. * Truncates the message to a max number of characters before printing. * Capitalizes the entire message before printing. * Stores messages in an internal list without printing. Part 2: Implement a search function within the store implemented in the fourth sub-of Part 1. I was not asked to write the code, only to discuss the approach. (Virtual Onsite - AI Coding): I was asked a variation of the camel card problem (which can also found in the site) (Virtual Onsite - System Design): I was asked to design a Google News aggregator. The interviewer asked about strategies for the API to poll data from third parties, and how to personalize the experience by allowing users to follow publishers and select favorite categories. Overall, I didn't fully understand what the AI coding was testing. My general strategy is to first discuss my ideas with the interviewer, then feed them to the AI to generate ideas and code, and then analyze whether what it wrote is correct before pasting it into the test environment. I didn't quite understand why the interviewer advised against pasting the entire problem into ChatGPT, but rephrasing it takes time and may leave out some problem constraints. I had this problem in both coding rounds, which led to spending some time debugging during the final testing phase.

Google

Software Engineer

Multiple TypesOnsiteMid-Level

In my first round, I was asked behavioral s covering AI ethics, how I organize team activities, and how I resolve conflicts. The coding was: Given a 2D matrix, find the longest path. You can only move up, down, left, or right. The next point must be smaller than the current point, or smaller than the point before the current one. For example, if moving from A to B, B <= A. Then moving from B to C, C <= B or C <= A. The second round coding was: Given an integer array starting from 1, imagine playing piano with one hand. Your hand can start at any position. Find the number of times you need to move your hand to play all the positions in the array. Example: [1,2,3,4,5] -> 0, [5,9,1] -> 1 The follow-up was to print the previous hand position each time the hand moves. Print the hand position at the end of the array as well. The third round coding was: Find the length of the longest increasing subarray in an array. The follow-up was to find the longest increasing length if you could change one number.

Nvidia

Master

YOE

6 yrs

CDN

Dropbox is a cloud storage and collaboration platform that lets users store, sync, and share files across devices. It is commonly used by individuals and teams to organize documents, collaborate on projects, and securely access files from anywhere. Over time, Dropbox has expanded beyond file storage into productivity tools like document workflows, e-signatures, and team collaboration features.

Design Google Doc

Real-time UpdatesWebSocket

Google Docs is an online document editor from Google, similar to Microsoft Word but cloud-based. It lets users create, edit, share, and collaborate on documents in real time. Since files are saved in Google Drive, people can access them from different devices and work together through comments, suggestions, and live editing.

Design Tinder

Cache(Redis)Elasticsearch

Tinder is a popular dating app where people create profiles with photos, a short bio, and basic personal details. Users swipe right if they are interested in someone and swipe left if they are not; when two people both swipe right, they “match” and can start chatting. It is commonly used for dating, casual conversations, and meeting new people nearby.

Design Google News

Cursor PaginationScaling Reads

Google News is a news aggregation product from Google that collects news articles from many publishers and organizes them by topic, source, location, and user interest. Instead of writing its own news, Google News crawls and indexes articles from news websites, then ranks and groups related stories so users can quickly see what is happening across different sources.

DesignHash MapSimulation

Implement a simplified in-memory inventory ledger that stores item profiles. Each profile is identified by a unique string itemId. A profile can contain multiple attribute-value pairs, where both the attribute and value are strings. --- Implement the InventoryLedger class: void putAttribute(String itemId, String attribute, String value) Inserts the attribute-value pair into the profile associated with itemId If the attribute already exists in that profile, overwrite its value If the profile does not exist, create it first String readAttribute(String itemId, String attribute) Returns the value stored for attribute in the profile identified by itemId If the profile or attribute does not exist, return "" boolean removeAttribute(String itemId, String attribute) Removes the attribute from the profile identified by itemId Returns true if the attribute was removed successfully Returns false if the profile or attribute does not exist If removing the attribute leaves the profile empty, remove the entire profile from the system ---

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