System Design Interview Questions

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

Karthik R. - "Good Discussion on the distributed messaging queues (Complex topic with lot of nuances) Liked the mind-map style drawing of requirements and metrics capture Touched on different types of queue styles (point to point, pub-sub, fan-out/fan-in) Storage and WAL usage was interesting Some distributed queue challenges that could be helpful to highlight / expand are: Message guarantee / semantics - Ordering of messages across different servers Replication Master slave architecture or Pe"See full answer

Dinar M. - " Thanks a lot for showing us how a recommender system can be build. I see it was proposed to use Collaborative filtering which is user - item matrix having dimension N * M (where N - number os users and M - number of songs). Though, it was explained how it gonna be built, it is still unclear how all users and songs features are going to be used. In that matrix we have values in cell (lets say i, j) like 1 - a specific user (i) clicked on song (j) when it was recommended or it is 0 when the user"See full answer

Eshan P. - "Background A. Objective Lyft has a presence in Toledo, Ohio. At our current revenue per ride of $6, we can match 60% consumers requesting a ride with a driver. Our goal is to maximize net revenues in the next 12 months by figuring out the optimal revenue per ride. B. TLDR Summary · With a target market of (~100K-138K) consumers, on a $25 charge to consumers, Lyft should pay $20.75 to drivers and fix its share at $4.25 to maximize its net revenues over a 12-mont"See full answer

Sai vuppalapati M. - "At a high level, the core challenge here revolves around building an effective recommendation algorithm for news. News is an inherently diverse category, spanning various topics and catering to a wide array of user types and personas, such as adults, business professionals, general readers, or specific cohorts with unique interests. Consequently, developing a single, one-size-fits-all recommendation algorithm is not feasible. To enhance the personalization of the news recommendation algorithm,"See full answer

Usman B. - "System Components Data Collection Layer Posts with hashtags are asynchronously sent to Kafka topics Each message contains: hashtag, timestamp, userid, postid Multiple Kafka partitions ensure scalability and fault tolerance Processing Layer Apache Flink processes streams in real-time Implements sliding window aggregation (1hr, 24hr, 7d windows) Calculates topic popularity using weighted metrics: Post count User engagement (likes, comments) Unique user"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

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

Eduardo C. - "I started asking some questions regarding the constrains of the system: An antena is emitting a signal that says if the tagged device was out of the room where the interview was happening. I was able to decide which would be the schema for the Antena's message. The antena is sending the info of multiple users. The system doesn't need to push notification to the users when the user left the device behind. Upon reflection, this is what I recollected doing. I propuse the json schema a"See full answer

Teja G. - "Modernizing banking legacy systems and applications The modernization process typically involves moving from mainframe-based legacy platforms to solutions based on cloud and other modern digital technologies"See full answer

El hassane B. - "Why this seems like a cyber-security question?"See full answer

Aymen D. - "It would have been more interesting to focus on the system design rather than the Trie DS, Interviewee could have just mentioned the Trie and passed to things more important. Interviewee should have focused on the factors on which he wants to scale the API servers, popularity of the query parts ? region may be ? A hash of many factors ? Caches should have definitely be discussed, Cache eviction policies, Cache invalidation managements... Interviewee should have mentioned which kind of API pro"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