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

Teja G. - "To design a scalable ticketing system for peak events like Black Friday, you must employ a microservices architecture, implement robust load balancing, leverage caching, and use a combination of NoSQL and relational databases for different data types. Key features also include real-time seat booking, secure payment integration, mobile compatibility with QR code validation, robust admin dashboards for analytics, and integrated marketing tools like promo codes. The system needs to prioritize avail"See full answer

Kiran M. - "I started off with developing microservices for the game and then incorporating kafka to make it scalable"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

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

Michael F. - "Prompt: We work for an online shopping website. Our team wants to consider offering discounts (e.g. 10% off your next purchase) to customers to incentivize them to make purchases. How would you design a system that decides how to offer these incentives? Answer Goals: Increase customer engagement while controlling costs. Specifically, we want the increase in revenue per customer per week of customers that receive the discount to be greater than the cost of the discount. Metrics: Revenue per cu"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

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

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

Clayton P. - "The interviewer hinted that a two-tower recommender system might be a suitable approach, using user history to embed users and pages separately and train on view or interaction data. Instead, I proposed a different approach that I felt was more aligned with how knowledge is structured in Confluence: I designed a system using a graph database to model the relationships between Confluence pages. Each page is a node, and edges represent content-based references. For example, when one article"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

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

Viet H. - "Estimate how much it costs Google to store a year free of storage of photos for new Pixel Phones Clarify with Questions Know the Basic Numbers Decide on and Lay Down Your Structure Write Down the Equations Crunch Numbers Sanity Check Clarify with Questions Are we talking about cost per person? Whole user base? What do you mean when you are talking costs? Cost to build the facility? Cost to just store the data as a result o"See full answer

San S. - "How might the system design change if it is limited specifically to a web/mobile use case?"See full answer