Warren

Software Engineer

Design a doctor appointment scheduling system. Doctors set their availabilities. Users can search for doctors and then choose time slots to book appointments for. How do you handle the race condition where two users try...

Software Engineer

Design a financial transaction processing system that lets users pay via credit card or ACH. ACH is slower and can take days while credit card is immediate. User should be notified on status of transaction. Deep dives ab...

Software Engineer

Implement Stream processing They give you some starter code, then you have to implement some stream processing logic in a class they give you. There are two steps to taking events off a stream: accept then process. There...

Software Engineer

I had a video phone screen for a position in one of the Ads teams at Twitch. This was an interview with the hiring manager. This interview was mostly a behavioral + technical screen. Behavioral: What is one time you and...

Staff Software Engineer

// Given an m x n 2D grid of '1's (land) and '0's (water), return the number of islands. // An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. // You may assume all fo...

Software engineer

You're given 2 huge integers represented by linked lists. Each linked list element is a number from o to 9999 that represents a number with exactly 4 digits. The represented number might have leading zeros. Your task is...

Senior Software Engineer

BACKGROUND Our autonomous penetration testing platform executes many concurrent pentests each day for our customers. As you can see in the diagram provided, findings during a pentest are stored in a temporary database. U...

Senior Software Engineer

You are given multiple configuration objects that represent different levels of overrides. Each configuration is a JSON like dictionary (map) that may contain nested dictionaries. Configurations are applied in order of i...

iOS, Android Engineer (Mobile)

Create a Worddle app Worddle is a game than user try to find a 5 letter word. They have 6 attempts to find the right word If a letter is correctly positioned, it's colored in Green If a letter is present in the word to g...

iOS, Android Engineer (Mobile)

1. Build a UI that display a list of people 1. This UI should display the list of people from this API: https://swapi.info/api/people?search="<user input ". The user can type which person they are looking for and the use...

Senior Software Engineer

Architecture Design: Mastercard Chargeback Gateway The Scenario When a customer disputes a credit card transaction in the Nubank app, we must process that request and notify the card network (Mastercard). However, Master...

Software Engineer

How would you scale a multi tenanted streaming system to accomodate spikes in traffic from a large enterprise customer without starving other tenants?

backend engineer

You have a graph of n nodes. You are given an integer n and an array edges where edges[i] = [ai, bi] indicates that there is an edge between ai and bi in the graph. Return the number of connected components in the graph....

Backend engineer

Design google docs

Backend engineer

Was asked to review a pull request. Focus on concurrency and thread safe access https://archive.ph/SV1h2

Security Site Reliability Engineer

Write a function that takes in byte[] as an input of structure: {0, 0, 0, 4, 1, 2, 3, 4 } size | actualMessage And passes the byte[] to some other function. But the size of the message can be more than the length of the...

Software engineer

Problem Statement (Polished): You are given an integer array delta , for example: [1, 3, 2, 8] . You start with an initial sum of 0 and traverse the array from left to right. At each index i , you add delta[i] to your ru...

Senior Software Engineer

Design social media app end to end. focus on live feed and ranking

Senior Software Engineer

Given an array of k lists, each list is sorted in ascending order. Merge all the lists into one sorted list and return it.

Senior AI Engineer

System Design Interview Question: High Volume Sensor Data Platform Design a scalable system to handle data ingestion from a large number of sensors. Requirements: The system should support millions of sensors sending dat...