System Design Interview Questions

Ketshi B. - "Clarifying questions When we say signals do you mean just features that are fed into the ML model that decide how the content should be ranked? Is newsfeed the front page of fb app. Can you expand what you mean by relevance? User journey User enters blue app.. Newsfeed is the first thing they see. User either continues on newsfeed ie scrolls through it or moves to a separate part of fb As they are scrolling they may see contents from friends, creators and ads, or other pages that they have been"See full answer

Chitapuram N. - "Since there is a need for the data to be accurate and consistent without any latency to allocate a spot, can't the data be synchronously synced to replicas after every write as the number of writes are not many per min, instead of read lock phenomena Let me know if i am on a wrong thought here."See full answer

dreamingincode - "In the API design, the interviewer is switching between RPC style (operation based endpoints) and REST style (resource oriented). Sticking to one convention and explaining why it is preferred over the other e.g. REST if the twitter domain maps nicely to resources e.g. /tweet or /follower or /user would help to create a more consistent and unified API. It would make it easier for clients to integrate with the API as well."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

Simon O. - "Functional Requirement Ingest Book Reviews in real time User in the website needs specify title tho search books, return response is the list of reviews on the books. Non Functional Requirement: User get real-time book reviews> It nees to handle the search among 1 million of active users daily"See full answer

Ramendra S. - "Step 1: Clarifying the Problem Scope We will focus on designing the leaderboard for Dream11 with these assumptions: Registered teams: 100,000 users are actively participating and ranked. Real-time updates: Leaderboard updates frequently as players accumulate points based on live sports events. Multiple leagues: Each user can participate in different leagues, so we will need to maintain a separate leaderboard for each league. Query efficiency: Users frequently"See full answer

Ankit M. - "Clarifying questions: When we talk about a 'meditation app', are we mainly focusing on audio content? And are we thinking of this under a big brand or are we a fresh startup? Also, is our main target the US? And, are we designing mainly for individual use, or are we thinking about larger settings like schools? Interviewer: It's a startup. We're aiming for individual users, mainly in the US, and yes, an audio-based format. Summary till now: In today's digital age there's an increasi"See full answer

Jacky Y. - "Problem scope: Can this system detect Bot in real-time online or offline? Both. Online traffic: 1M DAU. Latency: 2s. Offline frequency: daily Offline data: 2B activity logs. Data: How do we know a Bot player (Label)? Human label. Imbalance data: reweight, resample. Develop a Bot simulator to generate more data offline for training. Given lower weight to simulator data than human label. Features: Signals from different models online. Log all the features for offline. Propose new features: dail"See full answer

Scott S. - "Designing a Price Drop Tracker system like CamelCamelCamel involves creating a platform that tracks price changes for products on various e-commerce websites and notifies users when prices drop. Here’s a detailed system design for such a service: Functional Requirements User Registration and Authentication\: Users can register and log in. Support for social media logins (e.g., Google, Facebook). Product Tracking\: Users can add products to their watchlist for"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

Anshika R. - "Functional Requirement User should be able to add review the food item/order User should be able to rate the food item delivered User should be able to Like/Dislike others reviews User should be able to see all reviews on a food item Users should be able to receive rewards based on criteria- (Quality of the reviews- Based on number of likes - Monthly cash card) OOS - Item is already ordered and exists in a separate system, User is authenticated. No Media Non Functional requireme"See full answer

B. T. - "The interviewer was interested how the system design would be for files, directories, symbolic links. After proposing my idea, I was asked to print all files for a given path."See full answer

S V. - "I think, robots.txt file is provided by websites which web-crawler is crawling. Am I wrong somewhere or missing some context?"See full answer