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341
Design Instagram
Design a photo-sharing service like Instagram, where users can upload photos to share them with other users.
309
Design a Flash Sale Site
Limited number of items for sale with millions of active buyers fighting for remaining items
278
Create Distributed Cache
186
Design distributed rate limiter
- Design a horizontally scalable distributed rate limiting solution to prevent facebook's public api abuse
175
Payment System
A payment system similar to Stripe or PayPal.
158
Design Facebook post privacy functionality
Users have the ability to choose the privacy of their posts (Only me, Friends, Public). If possible, also get into Friends of friends and custom lists.
140
Design "likes" counter
Design a system that tracks the number of “likes” (posts / tweets / photos) at scale.
129
Design the auto-complete/type-ahead backend
Design the backend for an auto-complete system, like Meta, Google or Amazon.
124
Design CamelCamelCamel
price tracking system
115
Design a recommendation system for netflix/prime/Hulu to recommend movie
Design a recommendation system for netflix/prime/Hulu to recommend movies or TV shows
99
Deep Dive - DynamoDB
94
Deep Dive - PostgreSQL
93
Design meta chess
- Design meta chess. Store all the games and events and player moves. How do you design "undo" if each player can undo their last (or their two last) move(s)? Compute and maintain the scoreboard of billions of players? Top 100 games and winners.
82
Create Key/Value Store
81
Design Metrics Monitoring and Alerting System
69
Deep Dive - Cassandra
64
Deep Dive - Kafka
63
Design a leaderboard
User's have a list of friends and can see their leaderboard ranking among their friends and among global users. System should scale to millions of users per day.
62
Design distributed message queue
Functional Requirements - Client should be able to create a queue - Producer should be able to send message - Consumers should be able to receive messages - Consumer should be able to delete a message - delete queue.
62
Design Google Calendar
Design a calendar service that people can create events, invite others and suggest meeting rooms
51
Deep Dive Elastic Search
45
Design payment system
Lime Venmo, PayPal
45
Design Spotify
44
Distributed Logging and analysis
Petabytes of data per second ingestion, petabytes of data per second while querying.
43
Design a blob store like s3
42
Recoomendation system in Netflix
38
Design a notification service
Notification to other services or notification to users
35
Design ChatGPT
30
Design Status Search
Context: Every user can post something as "status", at any given time, one user can only have one status (vs multiple posts). Build a search system which should enable users to search the statuses.
30
Design a Parking Lot
29
Design meta chess
- Design meta chess. Store all the games and events and player moves. How do you design "undo" if each player can undo their last (or their two last) move(s)? Compute and maintain the scoreboard of billions of players? Top 100 games and winners.
27
Design a Single Server Memcached
Might also extend that to cluster level memcached as well.
26
Design Booking.com
Hotel booking app like Booking.com, Agoda etc
26
Design digital wallet
Users can check the wallet balance, add/view transactions and support transfer between accounts.
25
Design YouTube
23
Design CDN
we have to build content delivery network
23
Design web crawler
Meta twists this question a bit and asks peer to peer approach assuming we have 10,000 phones or machines and use those to crawl the web. No system design course has clearly demonstrated this so far, so I am really interested to see your take Evan.
23
Design Google Maps
21
Design GoogleMeet
Online realtime video conferencing tool
20
Transactions deep dive
Can you please explain how transactions work internally. For example how rollback will work in a simple in-memory key value store. Also it will be great if you can touch upon the distributed transactions. Thanks.
19
Design amazon product/inventory management
19
Design an E-Commerce System
Design an E-Commerce system with a functionality to handle billion $ sale days.
19
Design ZooKeeper
18
Design a Rate Limiter
18
Deep Drives Apach Flink
Five deep drives of Apach FLink and how to use it, why to use it and compare it with the other tool
17
Design a billing system
15
Design url shorter system.
Design distributed url shorter systems like tinyurl, linkedin etc.
15
Design Google News
Any news aggregator service
15
Tagging System
multiple services would like to store tags Cofluence for page, Jira for tickets and etc with CRUD and things like all pages per tag, dashboards and etc.
14
Google photos
12
Design FIFO Pubsub system
Design a Pubsub system that makes guarantee FIFO delivery. I was asked this question during my interview.
12
Design weather app
12
Deep Dives - Kafka
12
Job scheduler
- scheduling job - dag scheduling
11
How to design a Ledger System for Payment Gateway
Asked in Stripe
11
Design Live Video Streaming System
Designing a Live Video Streaming System Like ESPN
11
Design Zoom
wonder how this differs from designing whats app
10
Design Cab Sharing / Ride Sharing App
Multiple (3-4) user can share a cab, it can be either like Uber cab sharing or something like if I am driving from point a to b as a user I post that & anyone willing to travel on same route can pair with me and pay me for the part of ride, quickride
10
Design Twitter
10
Mock interview to get requirements
This is not an interview question specifically, but with both Evan and Stefan, I think it could be helpful to watch how an interviewee susses out requirements in a mock scenario without having practiced or knowing the problem.
10
Distribute 6M burgers in 10 minutes.
No one should get more than 1 burger. We should distribute exactly 6M burgers.
10
Design Shopify
Design Shopify, an e-commerce platform where users can easily create and manage isolated web stores with customizable templates, APIs, plugins, and automated hosting. Ensure scalability, security, and efficient monitoring and maintenance.
10
Design I18N and L10N system
- Build system that helps developers to add new strings in application - Also allow auditing of those string - string should handle pronouns, numbers, format, unit conversion etc.... - manual verification vs ML verification - enable translators
10
Design Online Judge
A online coding judge like Leetcode which hosts coding contests, allows users to test and submit code, tallies scores and maintains a leaderboard
9
Design chess game between human and ai
- Determine how points are assigned for every move and how to determine winner/looser/draw state
9
Deep Dive - ETCD/Zookeeper
8
Design a food delivery app
A food delivery app like doordash or swiggy or zomato
8
Design Proximity Service like Yelp
8
Design subscription system
Got asked at Google
8
Design Slack
7
Design Amazon Lockers
1. User can select nearby lockers at checkout. 2. System should generate OTP until used by user to unlock locker.
7
Distributed high scale telemetry system
Telemetry/Metrics system such as Datadog, Splunk etc
7
Design google calendar
Focusing on the notification system (users can be in different time zones, each reminder should be sent only once, set reminders with frequency/interval, i.e. once a week, twice a month, etc.)
7
Design a Feature Flag System
- Millions of users - Target individual users and % of users - Admin UI - Backend only
7
Design Machine Learning Platform
7
Design WhatsApp
7
Design Google Calendar
google calendar - unique link generation, emphasis on how to store a meeting invite with multiple participants - which is recurring, reads (across globe) and writes - create, update, delete are efficient
7
design Chat GPT
7
Design Live Streaming System
Like Hotstar, Youtube or Netflix where millions of users are watching concurrently. How to minimize the live feed latency and scale for sudden spike and drop in traffic. System should be able to handle 50M-100M concurrent users at a time.
7
Deep Dive MapReduce
MapReduce, Hadoop, HBase, Hive..
7
Design a bidding system
Where users can bid
6
Design Steam
Game creators, can create new games, publish and upload files. Users can search for games, add to cart, buy and download.
6
Design YouTube
6
Blocking IPs from a specific country
We can't serve data to banned IP addresses. This country exposes a web interface - http://security.gov.x/ - that just tells us for any given IP address if it’s banned or not. you have to solve it within two months so no need hot fix but no redesign.
6
HTTP downloader
6
Design Advertising Platform for Ad Reporting
1. Analytical Load Serving 2. Data Skewness handling 3. Realtime Reporting
6
PSP like VISA
Design a payment service provider like VISA.
6
Design google calendar
Focusing on the notification system (users can set reminders with frequency/interval, i.e. once a week, twice a month, etc.)
6
Design Gmail/Outlook
send and receive an email including attachments, filter and search through emails, and add tags to label emails
6
Designing a key value store like Redis
6
Design a Notification Delivery System.
Something like One signal.
6
Design Code Deployment
Global and fast code deployment system.The system take the code. Builds the code into a binary and deploys the code globally in an efficient way. scale and deploy code to application servers all around the world. Addition NF requirements
6
Design a Distributed Job Scheduler for Millions of Tasks in Daily Operation
6
Design a hotel booking system
6
Design Stock Exchange
A lot of system design for stock exchanges out there focus on distributed systems rather than the requirement of low latency order matching which should be done in memory rather than utilizing queues and what not. Would love your perspective
6
Design Robinhood
- Live stock price updates per second of 7000 tickers - Getting historical data of a stock for a timeframe for displaying the chart. The stock exchange in this case gives all the data points for a stock. For 1 month, all the data points each second
6
Design Twitter/ X Trending hashtags
Find top k hastags based on location and category. User can also search for past trending hastags
5
Design a reminder service
Users can schedule a onetime or recurring reminder which will send an email / push notification to the user. The reminder should be delivered exactly once within 5 minutes of the time. It should scale to millions of users.
5
Design whatsapp/messenger
5
Design a money transfer application
5
Deep dive on Elastic Search
5
Design a webhook
A webhook can be a POST http endpoint called by an authenticated third party client. The client will call the webhook with a url and a message payload. The webhook should lookup the URL in the internal database registry and send the message to it.
5
Design a banking app
5
Deep DIves: Apache Flink
5
Deep Dive: TimeSeries Database
4
Design a time series db
4
Design an in-memory db
4
Design a rate limiter
4
Create Distributed Cache
4
Design credit card system
System to process millions of transactions, always validating the customer's limit in every transaction
4
Design Distributed Logging/Tracing
A system like jaeger
4
Design Peer to Peer Payment System
Like Venmo/Cash app allowing people to send money to other people.
4
Design a multiplayer game matchmaking system
User's should be able to join matches of 12 players. Matching should be as fast as possible while keeping players close together. Players should be matched on their skill level (Win:Loss ratio etc). Should support ~1M players concurrently.
4
Designing a Music Recognition System like Shazam
system should be able to identify a song by listening to a short audio clip provided by the user. Once identified, the system should return details about the song, including the title, artist, album, and a link to listen to the full track.
4
Explore Distributed Concurrency Control
Go deeper into concurrency control between multiple instances of a microservice. For example, in the Ticket Master exercise, explore how we could control the concurrency when multiple instances of the Booking microservice tries reservice same ticket
4
Design Paypal
4
Design Splunk - Logging and Metrics Monitoring System
4
Design a typeahead feature
4
Deep dive - Zookeeper
4
Deep Dive on API design: RestAPI and GraphQL
3
Planet Scale Metrics Ingestion Platform
Backend infrastructure for a metrics platform that scales for several zones/regions across the globe for ingestion and support queries for alerts, and on-demand incident response
3
Design video sharing website (twitch) copyright video detection
Design a service similar to twitch that flags and deletes copyrighted audio in videos if another user has uploaded it (copyright infringement)
3
Web Crawler
Design a webcrawler
3
Design a payroll system
For HR type software
3
We could use a dark mode on this site
3
Design a price alert system
3
Design a distributed counter
3
design jenkins
Design CI/CD system such as jenkins.
3
Design Coding Contest Platform
3
Design Version Control system
Design a system like github
3
Design a Fitness app
Tracks biometrics based on geolocation and activity
3
Deep Dive - Raft v/s Paxos
3
Recommendation Systems
Video recommendation, Product recommendation etc..
3
Secure System Design for existing problems
Would be great to have some examples on how to approach secure system design interviews. Most of these focus on the SWE perspective but would be helpful to refocus around security engineering interviews.
3
Design Snapchat
3
Design Github/Gitlab
3
Design Robinhood
Robinhood - how it gives real time stock data and handles market crashes
3
Create a digital wallet
3
short url system design
system design for generating short urls and routing the short urls
3
Design a proximity Service
3
Deep Dive - ElasticSearch
3
Design Google sheets
3
Design Tiktok
short video platform such as Tiktok, youtube shorts, etc.
3
Design Block Storage System .
I was asked this question within Amazon . The question is "Design a block storage system that can reduce the fragmentation of the disk and provide durable storage devices on demand" . Something like AWS Elastic Block Storage.
3
Design a distributed load balancer
Distributed load balancer optimising for different work loads
3
Design the Google Doc
3
Deep Dives - Kubernetes
3
Design IAM system
3
Design Robinhood/Stock trading platform
System that can be more as an orchestrator between client and stock exchange for real-time prices. Also, execute trade with the lowest possible latency similar problem that hfts trying to solve to make the highest profit.
3
Design Food Deloivery App
Design food delivery app like UberEats, Doordash
3
Online Bank
Design online banking system
3
Design Amazon
E-Commerce checkout!
3
Design Weather App
Design a weather app that would retrieve data from NWS in hourly fashion When a user requests for weather data, he should get the most recent one. <10 stale data is acceptable
3
Design Mint like platform
A personal financial management platform for comprehensive view of finances in secure way.
3
Flights Aggregator - Skyscanner
3
Design Instagram Live
2
Job Scheduling
Design a scalable job schedulable that can schedule jobs in a perodic mannner
2
Design IFTTT
2
Design a messaging queue like Kafka
2
Design ACL like Notion
In Notion ACL can be implemented on individuals, group of individuals as well as on pages where if a user has access to parent page then the user also has access to all the child/nested page.
2
Tagging service system design
https://leetcode.com/discuss/interview-question/system-design/838025/Design-a-tagging-system-like-tags-used-in-stack-overflow
2
Design a distributed lock with TTL
2
Design what database to choose
This is more kind of an overview. Can you guys make a video on what database needs to be chosen for different type of use cases.
2
Continuous Integration System
2
Design Youtube
Design Youtube for upload, search and view features
2
Design of Amazon Product Review System
Design of Amazon product review system, write and read part especially during sale periods
2
Design real-time livescore sport
Like SofaScore, where Users can watch what is happening real time in a particular match. Taking care of important matches like World Cup Final or Super Bowl with inputs flowing manually or automatic from stadiums
2
Views and likes of a post in twitter(X)
Design a scalable system to handle the millions of views and likes of post in twitter. We should be able to scale for both read and write
2
Design Zillow
2
Sports Live Streaming
Streaming sports matches to millions of users in real time.
2
Gmail
2
Phising detection system
Design a phising detection system
2
Phising detection system
Design a phising detection system
2
Online Stock brokerage
2
Design Venmo/Paypal
Fintech being on the rise, design a system like venmo or paypal that makes it easy for users to send/receive money to/from each other. Staff/Senior: After you've implemented the system, discuss the security implementation you would consider.
2
Design Shopify
2
Design a telemetric service
All the services that are deployed in a organization can send their such as cpu/memory/ etc. These information can also be used by alerting/alarming service to alarm
2
Design a chat app
Design a chat app that support instant messaging (1-1, group chat).
2
Design a file system
Design a file system that can store 100s of PB of data. It offers POSIX semantics.
2
Design an ad serving system
Design a real time ad serving system for digital ads
2
Design a HighFrequency Trading Platform
2
Design a hotel reservation system
Hotel reservation system question has some nuances. It can be as simple as a single hotel reservation to all the way up to a hotel chain reservation. This is different from Booking.com, as that site doesn't handle the actual reservation itself.
2
Deep dive data warehouses
2
Design Zoom
2
Tag service
2
Design Realtime analytics dashboard
2
Design Tiktok
2
Design Instagram Story
2
Distributed counter
It has many use cases like: 1. Count of unique concurrent users logged in to a system 2. Count of a particular doc opened by user. 3. Count of likes on a post. The count value should be near real time.
2
Design e-wallet
2
Deep Dive - Zookeeper
2
Design a Telemetry Sysytem
Like Prometheus. Connect with external apps, record metrics, failures, events and logging.
2
E commerce
2
SQL vs NoSQL
During the design which DB is best suited for the particular requirement and why ? Pros/Cons of it
2
Design Reddit
Forum for discussion
2
Deep Dive - Spark
2
Design Recommendation System
Something like Amazon's "Customers who bought this, also bought these N items"
2
deep dive into flink
1
Klarna System Design
1
Design Stadia like gaming service with top player leaderboards
Imagine that Youtube team would like to start advertising games before video begins. The ad will allow you play for 2 minutes and offer a link to purchase a game after that + leaderboards. Can you succeed where Google failed?
1
Design a location based service like Yelp
1
Create Distributed Cache
1
Design a distributed auto increment id generator(should be ascending order)
1
Design wikipedia
1
Design a centralized notification system
A social media app sends multiple notification to users. Different notifications are owned by different teams. Create a system which will be used by various team to send notifications immediately or in future.
1
Design Whatsapp or Facebook Messenger
1
Get active events
System has handlers set_start(id, ts) and set_finish(id, ts). Incoming data via these endpoints are quite high. The finish event can come before the start event. What's the optimal way to calculate getActiveEvents(ts)?
1
Design Global Counter
1
Design youtube shorts
1
Design a therapy booking platform
like betterhelp or growtherapy
1
Design a build service for multi region cloud
1
sentry.io
Design a sentry.io like system
1
design YouTube
Youtube/ Netflix
1
Design Street View in Google Map
1
Design youtube likes
Users see likes on videos with low latency
1
photo sharing app like Instagram
1
design online Pong Game
players can join, and need to be matched with someone else who is online
1
Design a virtual agent
Design a virtual agent (retail/commerce/etc) which interacts with customers from a web or any other interface to understand the customer's questions and respond based on the company's or org's knowledge repository and any off the shelf LLMs (RAG)
1
Design amazon locker
1
Design Talent assessment platform & a resume screening/tracking system
Design Talent assessment platform like hirevue and a resume screening/tracking platform.
1
Design a Reminder application
1
Design a Traffic Light Control System for a city
1
Typo
Handling Big Data and Real-Time Web Apps: You have an applications dealing with large volumes of data, especially unstructured data, or applications requiring real-time data processing and analytics. an applications is wrong
1
Below looks not right. Could you confirm
Message Ordering: However, some queues (like Kafka) allow for more complex ordering guarantees, such as ordering based on a specified priority or time.
1
Design a hotel aggregator system where user can book a room
1
Design a social media application for introverts.
1
Design a ledger system
common question for fin tech, design a ledger system can record money movement and account balance.
1
Design Block Storage System .
I was asked this question within Amazon . The question is "Design a block storage system that can reduce the fragmentation of the disk and provide durable storage devices on demand" . Something like AWS Elastic Block Storage.
1
Design Stripe/Plaid
1
Open AI
1
Internal company tool
placed in charge of a large application - runs in a single data center - all stored there and all processing serving and traffic is done there -multi data store -multi app server - serving diff portions of app design tool to monitor performance
1
Design code coverage tool
1
Design a centralized video update management system
Design a centralized video update management system that integrates with mu
1
Design a Marketplace System
1
Design figjam with multiplayer support
Figjam with comments and comment replies, with real time updates
1
Design multiplayer chess with leaderboard
Multiplayer chess system design - similar to chess.com, competition, leaderboard, etc.
1
Design Snapchat
main requirements : 1. sending of snap to one another/group 2. stories 3. snap score
1
Design a Bookkeeping System for Tracking Personal or Business Financial Tra
A bookkeeping system is used to record and manage financial transactions, such as income, expenses, and transfers. It helps individuals or businesses keep track of their financial activities, generate reports, and ensure accurate financial management
1
Deep Dives - Zookeeper
1
Designing a URL Shortening service like TinyURL
1
Design a Connector between Tiktok to its vendor like Amazon/Shopify
1
Design a Currency Converter
1
Design Common Components
Basically multiple design questions that explain how to design MQs or Blob Stores or Rate Limiters or Load Balancers...etc common components we would use in product design questions
1
Distributed Key Generation Service
A system to support idempotency transactions.
1
Design VirusTotal
Users can upload file(s) to be scanned by multiple anti-virus engines and metadata scripts. Provide results close to real-time as possible. Scale to millions of users.
1
Stock Broking System
- Frequent update stock price which will reflects on Millions of end users - Order execution partially or fully - Event base order executions like Stop loss
1
Design ChatGPT
design LLm model using prompts. Emphasize on Scalability availability and how model should be trained
1
Distributed File Transfer System
- Get one large file to thousands of servers in short time - System design specifically focused for Production Engineering role at Meta
1
Production Engineer System Design
- Design Problems asked in production engineering role - Doing OS upgrade in scale, automation etc
1
Design LinkedIn
1
Design BrowserStack
Executing UI tests in multiple browser instances concurrently.
1
Metrics Monitoring and Alerting system
Metrics Monitoring and Alerting system
1
design a instagram
Upload, view posts able to send images and videos
1
Collabarative text edit like GoogleDoc
- collabarative text edit - simple styling - different type of clients
1
Ebay Auction Site
Highly consistent, low latency and scalable system
1
Design a real-time fraud detection system
Design a system that extracts transactional data, apply complex transformations (e.g. anomaly detection, pattern matching), and load results into a monitoring or alerting system in near real-time.
1
Design GitHub
Repositories' version control system
1
Design Webhook
1
design payload
1
Design LRU Cache
1
google maps
1
Design Live video streaming platform
System like hotstar which streams worldcup matches for 10 M users concurrently
1
Design notification system
How would you 90M followers of a celebrity that they are going live
1
Design Instagram story
1
Deepdive MongoDB
1
Design Online Multiplayer Gaming Platform
1
Design TrueCaller
1
Design a zero-downtime data migration system
Intrigued by the logical replication section in the PostgreSQL deep dive, it would be interesting to see how data migrations are done at scale.
1
Design like .mint app
1
Design an authentication service
An IdP like Okta that can perform federation and access to cloud-based apps.
1
Deign Google Photos
1
Centralized System for Authorization
Design a central Authorization system that's capable of handling any combination of user(s)/entity/column level restriction centrally (similar to Google’s Zanzibar)
1
Design an online multiplayer game system
1
Design a voting system
users can cast multiple votes, latest vote counts. High accuracy vs low latency(real time) design
1
Deep Dive - Neo4J / Graph Database
1