System Design Interview Questions

Xash C. - "This one is a great example of Build, Borrow, or Buy strategy framework (http://www.build-borrow-buy.com/build-borrow-or-buy-in-practice/) - explore and evaluate three different approaches: organic growth and building a product from scratch (e.g. Amazon building its own Amazon Restaurants service), partnering with an existing provider (e.g. enterprise-level partnership with Instacart or Lyft), or acquisition growth (e.g. Uber acquiring Postmates). Evaluate which approach makes sense for the com"See full answer

Sneha D. - "Created a solution for remote online learning app on the lines of coursera and also made a option for live streaming classes . Uni admin creates uni account, courses, adds instructors; instructors can create content , give classes ; student searches, enrols, consumes content. Used micro services architecture with APIs for all functions, RDBMS, NoSQL , indexed with redis and elastic."See full answer

Mark - "Clarifying questions: What's Lyft current goal and how does this new focus on Deaf drivers align with Lyft's goal & strategy? Do Lyft already have service/product to enable deaf users to drive for lyft? Assume We don't have any existing product/service to allow deaf users to drive for Lyft today We are designing for the ridesharing business and that the Deaf drivers can drive for all types of Lyft rideshare options Lyft's Mission: Improve people's lives w/ the world's best transport"See full answer

Karthik M. - "Structure Why should we build this? + market, company, product, trends Users Painpoints Solutions Summary Clarify company - 0 to 1 Why should build this Market factors Size and opportunity (tam) sizeable market - billions of dollars in TAM Competitors (1) governments (2) parkmobile (3) vendors for each parking lot (parking structures / lots, man people) Strengths Parkmobile - available anywh"See full answer

Anonymous Parrotfish - "when and where?"See full answer

Sunny G. - "https://en.wikipedia.org/wiki/Operational_transformation"See full answer

Deepti K. - "I gave multiple answers including polling the service every 10 sec to see customer. Or we can have the client side call which will send this data after 10 sec to us. We will store in dynamo DB and then send through pipelines to redshift DB for analytics."See full answer

Ian R. - "You might build a product like this a few ways. I think you'd definitely want a temperature sensor device (maybe like a TMP422, or maybe there's a different one that is standard for wearables) that was worn by the individual. As far as tracking social distance, my answer here is more dependent on the state of the art of robust (wearable) distance measurement. Maybe there's something available better than ultrasonic sensors, maybe there's some kind of electromagnetism based solution that isn't in"See full answer

William W. - "Clarifying questions Why is this company interested in building a vending machine for disabled people? We're a vending machine company who has recently learned that disabled people have a lot of trouble using our machines. We want to change that. What is the main metric this company is trying to drive? Machine usage Is there a specific kind of disability we are interested in targeting? Blind, amputees etc. Blind/vision impaired people Is there a specific type"See full answer

Anonymous - "Functional requirements: (a) location tracking (b) check-in at nearby place (c) view historical checkins with how much time user stayed there (d) Mark checkout when out of proximity (e) analytics - checkins by user at given loc, top n places Out of scope: (a) checkin sharing with followers Non functional: (a) low latency (b) high availability (c) eventual consistency Scale: (a) QPS: 10M DAU * 2 checkins /86400 seconds (b) Yearly Data Volume: 10M* 0.1 KB *365 days HLD: user -> location servic"See full answer

Nilanjan D. - "I think we can analyse the data that's collected especially the users who are requesting it.if we find that there are set of users who regularly use this service then we may cache the data for those users to speed up processing and better the experience. The fresh data (which will be a delta on the cached data can only be calculated) and the stale data can be left out thereby updating the cache"See full answer

Darshak S. - "Clarifying Questions: There are several different types of therapists, do you have a particular therapist in mind? Like Mental health, physical health, food and nutrition etc? Reply: You can decide And do we know what country are we building this product, since that will help me narrow down the scope of the product? Reply: USA Approach: Define the product vision and the goal that we want to achieve Target Audience is for this particular product What problems do these user currently"See full answer