System Design Interview Questions

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

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

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

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

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

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

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

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

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

Anubhav S. - " At low level: I would use two stacks: one for forward history and other for backward history. i go to tryexponent.com => this url will be stored in backward history stack. i go to google => again this url will be stored in backward history stack. i press back => data from backward history will be popped and put in to forward history stack. I press forward => data from forward history stack will be popped and put in to backward history tab. Also, whenever i go to any url,"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

Robert H. - "The addition of an intermediate "sanitization" ML is something Neeraj used in the Uber Eats design and again seems kind of outside the scope here and redundant. This can simply be built into the AI response model to save a step. It's not clear what benefit this step provides, and he basically said we should have it "just because it would be good" and there's no concrete reasoning why to include it. Adding a Kafka queue to handle the thumbs-down ratings? For what purpose do you need a queue othe"See full answer

Kapil D. - "Overall a very good summary of ranking problems. I wish there are more details in the post on depth of modeling. One can talk more about advance ML architectures like DCN, BertRec etc"See full answer

S R. - "Wrote up a simple cache system using python dict. Added TTL requirement. Then went into code-level concurrency issues for the cache."See full answer