Google System Design Interview Questions

Manjula R. - "Clarifying questions: What is the issue in the current algorithm? Not obvious Why do you want to improve? Engagement Are there any churn trend in YouTube viewers? Yes I see for last few months 10% reduction Do you have any support tickets from users regarding personalization? Not sure Have you released any new launches or bug fix into the existing algorithm? No What is the goal for this improvement suggestion? Engagement Are you targeting any specific region? NA Do"See full answer

Shahnawaz A. - "Came up with following strategy: take logs from user and send to LogService via API GW LogService takes the responsibility of generating time based SequenceId and persist the log in NoSQL (DDB) with key as SequenceId as primary key and timein_millis as sort (secondary) key. There are many system design tutorials on generating sequential sequence id where prefix is current time in epoch (milliseconds) Since there would be many LogService servers, spread across different availability zo"See full answer

Million D. - "Machine learning software engineer interviews at Google are really challenging. The questions are difficult, specific to Google, and they cover a wide range of topics."See full answer

Palak A. - "Designing a system to deny services to requests from banned IPs involves integrating real-time IP checking with your service architecture. Here’s a detailed outline of how you can design such a system: System Design Overview The goal is to ensure that your service can efficiently check incoming requests against a list of banned IPs and deny access when necessary. The system will leverage an external API, security.gov.x, to determine if an IP address is blocked or allowed. **Key Compone"See full answer

Yespm T. - "Clarifying question: When you say users, what specific metric are we talking about?  Answer: we want to increase # of daily active users.  Assume active users are logged in users. Is there a region that we have in mind for this increase? Assume no, we want to think about globally Is there a specific device (mobile vs desktop) ? Assume no Approach: I want to first think about Youtube, its mission and current business at a high level. . Then I want to think about the current ecos"See full answer

Bella R. - "Approach Clarify the question Define deaf --> unable to hear, but can communicate via sign language, lip read and use all other senses Define fire alarm --> for residential use, it notifies occupants of smoke and potential fires and alerts fire department to check in and/or come over Define constraints --> budgetary constraint, design should be user-friendly and convenient Define goals --> get folks out of harm's way quickly and notify fire department to c"See full answer

Rjj - "I tried solving this problem and here is the recorded video for the answer. https://www.youtube.com/watch?v=d1tOkeQjyI4 And here is the link to Excalidraw board - https://excalidraw.com/#json=uabNFHcZm5qNh8CInMvyh,Wn9Vf1ZhGdl_iBCQYFkYdw"See full answer

anush - "@Jacob, your videos are really good and helpful. I want to know about the tool, you use for explaining the design in the videos."See full answer

Ashish G. - "Rate Limiter is to limit the number of request from a particular IP Address. Rate limiter will block the IP address to reduce the load on server. It should be highly available and handle concurrent requests. Blocked IP addresses should be kept in a pool which is present in shared cache. We need to keep threshold value after it reaches threshold value it should start blocking IP address. All these ip address to be kept in No SQL DB. Batch will run that will clear the cache and delete all the bloc"See full answer

Kshitij A. - "The question is bit vague (I guess deliberately) so I believe firstly we shall ask questions and resolve ambiguity. Some initial questions could be : 1) Is this one time activity or something that should be done on continuous basis. If continuous basis then at what frequency. 2) How much staleness is acceptable in SYSTEM Y data 3) Are there any limitation in SYSTEM Y and is it fair to assume that we would need some kind of transformation to bring data into SYSTEM Y schema. 4) What kind of vol"See full answer

Harshit G. - "Great. I will start by understanding the goal of Google Photos and how it aligns with the goal and mission of Google. After defining goals, I will talk about the user actions which will contribute towards this goal. Based on these actions, we will define metrics. Check-in with the interviewer on the approach here. Assuming that this looks good for the interviewer to proceed. Google Photo - Helping users organise & manage their pictures. Completely in line with Google's mission. Thinking ab"See full answer

Vivek G. - "Which tool we should use while system design interview"See full answer

Shivastuti K. - "For somebody who needs accessibility accommodation, this doesn't have a transcript so it is not useful to me."See full answer

Nitika B. - "Equation: Cost = Amount of storage required per year * Cost per year * 3 Amount of storage required per year = DAU * Storage requirement/user * 365 Assumptions: Cost per year = $99 = $100 Smart phone growth rate = 2% (But negligible at Pixel level) Annual Smart phone users = 2.8B Android users = 76% Google Pixel users = 1% Total Users = 2.8B * 0.01 = 280M *0.01 = 2.8M Method 1: Cost = Active Users + Cost/year * Number of years Cost = 3* 2.8M * $100 = 8.4M*100 = $840M Cost = $8.4B Method 2: C"See full answer

Praveen - "I will start with discussing the Google mission statement, which is to organize the world's information and make it easily accessible to everyone to help them get things done, and make their day a bit easier. I will think about building something that will leapfrog this mission. Google has already organized all of the world's public digital information in the current state. There are opportunities to get more information into a digital form. But there are also significant improvements in mak"See full answer

Srinivasa R. - "Any more details about this can make it easy"See full answer