System Design Interview Questions

Teja G. - "separate your application into three distinct layers: a Presentation Tier for the user interface, an Application Tier for business logic, and a Data Tier for data storage. Implement each tier using appropriate technologies, deploy them across different network segments for security, and configure communication protocols to allow for independent management and scaling."See full answer

Qusai B. - "Assumption: I’m estimating the minimum number of trains required to fulfil maximum demand I’m including all trains that’s serving NYC Formula: Before I state my formula, I would like to mention a few things I will be calculating the number of trains required to fulfill all demand at the peak time during a workday. I assume peak time lasts for 2 hours I’m assuming that a train takes 2 hours to complete one roundtrip on its route, which means any given train can service rider"See full answer

Deepak K. - "FN Given text need to figure out is it following guidelines. Should notify the user in case of not following guidelines. Reason for failure should have misleading/spam/adult filters. NFN High availability High Scalability Low latency of processing Estimations 1M requests/min text - 10kb => 9.5GB/min => 14TB/day API fetchmoderationscore(text) score will be between 0 to 1 more than 0.8 => not following guidelines fetchmoderationscore(text, filter)"See full answer

John N. - "There are several factors that I can employ to come up with a dynamic pricing system that has capability and capacity to adjust product or service prices based on the various parameters or factors that affect market prices such as demand and supply. This will be built on customer behaviours, competitors, demographics, and other relevant variables at my disposal. First, I will define the Requirements and Goals of the system. what is the business needs that this dynamic system will cater. Here fa"See full answer

Yag S. - "I studied Exponent's TinyURL system design video. My interviewer was asking many detailed questions on API design, schema, as well as data required to store. I found system design questions are bit high level instead of depth. I think should have detail design of API, schema and some additional flavors."See full answer

P K. - "Note: Modifying the question to reflect the storage cost as well. Question: Estimate the cost of storing google photos on the photos app? Clarifying questions: Google photos - an app that syncs automatically to your camera app and uploads photos to Google cloud and reduces the need to store it on your device Cost of 1GB storage $0.002 Time storage cost per year Equation: Cost of storage per year = average cost of storing photos per day x 30 days x 12 months The ave"See full answer

Amit T. - "Question Design a product for P2P borrowing & lending money Clarifications Is this only P2P borrowing/lending or can financial entities participate too? - P2P only Is it to borrow/lend physical cash/digital money/cryptocurrency? - digital fiat money Are we focusing on specific geography? - US What’s the goal of this product? - Retention Are there any resource constraints? - No What’s the timeline to launch MVP? - 6 months FB Mission Empower people to build commun"See full answer

Nilanjan D. - "Amazon Prime will generally have a limited group of uploaders rather than a million of them. This should influence the design of the Uploader service as it doesn't need to scale that much. Also the Encoding service role was not too clear"See full answer

Sri A. - "Mission: to help users buy and sell products from groups. If we think about the value here, users want to join groups that sell/buy products of interest (young moms or vinyl), or location of interest, or trust, or some other factor - either from other users or SMBs. User Actions: create groups, join groups, active in groups - make posts to sell or show interest in buying (like, commenting, sharing or ideally transacting) deeper engagement - sharing , saving , searching more based on wh"See full answer

Kai W. - "The user awakes Alexa by saying the "Alexa word" Device starts recording audio from the user, and streaming it to the Alexa Cloud Service The recorded audio stream is sent to the ASR (Automatic Speech Recognition) system ASR returns the words and the order of the words in the audio stream, and sends this information to NLU (Natural Language Understanding) NLU returns the intent of the audio stream, and sends it to Alexa Skill If the intent triggers a "play" directive (e.g. turn"See full answer