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HelloInterview Questions to Archetype Composition #

This file maps each question in hellointerview_questions.md to a composition of the local archetypes in this repo.

Interpretation rule:

  • Primary = dominant write/read shape I would start the interview from
  • Secondary and Tertiary = supporting shapes that usually appear once the prompt expands
  • This is a closest-fit composition using the repo’s existing archetype vocabulary, not a claim that every prompt is perfectly covered by only one archetype

Archetype legend:

  • A01 = Current-Value Entity
  • A02 = Relation / Edge
  • A03 = Append-Only Child Object
  • A04 = Workflow / Lifecycle State
  • A05 = Derived Projection
  • A06 = Inventory / Constrained Resource
  • A07 = Critical Transaction Process
  • A08 = Time-Bounded Exclusive Allocation
  • A09 = Future Constraint + Claimable Run
  • A10 = Frontier + Claimable Run
  • A11 = Control Plane + Local Snapshot
  • A12 = Matching / Assignment
  • A13 = Ranking / Leaderboard
  • A14 = Realtime Fanout
  • A15 = Search-First Product
  • A16 = Auction / Competitive Window
  • A17 = Shared Mutable Subject
  • A18 = Versioned Namespace + Immutable Content Units
  • A19 = Catalog + Scoped Relation
#QuestionPrimarySecondaryTertiary
1Design TinyURLA01A05-
2Design TicketmasterA06A08A07
3Design Rate LimiterA05A04-
4Design DropboxA18A05-
5Design a Distributed CounterA05A13-
6Design a Food Delivery App Like DoorDashA12A04A14
7Design Facebook News FeedA05A14A03
8Design Webhook ServiceA09A04A14
9Design YelpA15A05A03
10Design a Notification SystemA14A09A04
11Design TypeaheadA15A05A13
12Design SlackA14A03A05
13Design UberA12A04A14
14Design Google DocsA17A14A18
15Design InstagramA05A03A14
16Design a Payment SystemA07A04A05
17Design TinderA12A05A14
18Design a Key-Value StoreA17A18-
19Design WhatsAppA14A03A05
20Design SpotifyA05A18A15
21Design a Distributed CacheA05A17-
22Design Google DriveA18A05-
23Design a Search Autocomplete SystemA15A05A13
24Design LeetCodeA04A13A09
25Design AmazonA15A04A05
26Design a Web CrawlerA10A15A05
27Design an Ad Click AggregatorA13A05A14
28Design a Resource Loader in a Game EngineA18A05-
29Design Recommender SystemA05A13-
30Design a Review and Reward System for Food DeliveryA03A07A04
31Design a Distributed File SystemA18A17-
32Design Facebook Live CommentsA14A03A05
33Design a ledgerA07A04-
34Design a Calendar SystemA04A05-
35Design a crossword puzzle serviceA09A05-
36Design Netflix Subscription BillingA07A04A09
37Design Status SearchA15A05A03
38Design a Review App for Food ItemsA03A13A07
39Design a Feature Flag ServiceA11A18A05
40Design a Driver Heatmap SystemA05A14A13
41Design a cloud storage system like Amazon S3A18A05-
42Design a System Metrics Monitoring and Alerting PlatformA05A14A09
43Design a Ci/Cd PipelineA09A04A12
44Design a URL ShortenerA01A05-
45Design YouTubeA18A05A14
46Design a Malicious IP Detection SystemA15A05A14
47Design Online Auction SystemA16A14A04
48Design TwitterA05A14A03
49Design a skill-based matchmaking systemA12A13A14
50Design an analytics dashboard for an AI chat appA05A13A14
51Design a large model file distribution systemA18A14A05
52Design an Online Game LeaderboardA13A05A14
53Design Github ActionsA09A04A12
54Design a stock trading platformA16A07A04
55Design Google DocsA17A14A18
56Design Stock price alerting systemA09A14A05
57Design Post SearchA15A05A03
58Design a devbox systemA18A04A09
59Design a visa payment network system for transaction processingA07A04-
60Design a Navigation/Mapping SystemA15A05A14
61Design a Key-Value StoreA17A18-
62Design a Top-K SystemA13A05-
63Design SlackA14A03A05
64Design Vaccine eligibility and booking flowA06A04A08
65Design a credit card system with approval of paymentsA07A04A05
66Design a Like/Unlike FeatureA04A05A13
67Design Top K Songs Display SystemA13A05-
68Design CoderPadA17A14-
69Design a personal finance trackerA18A05A04
70Design a Banking SystemA07A04A05
71Design Asset Price Management SystemA05A14A13
72Design a Delayed Payment Scheduler ServiceA09A07A04
73Design a Publisher-Subscriber Message queueA14A03A09
74Design a 911 Call CenterA12A04A14
75Design a credit card management and offers systemA07A05A04
76Design an Ad ServerA16A05A14
77Design a Facebook posts storage systemA03A05-
78Design i18nA11A18A05
79Design UberA12A04A14
80Design a Banking ApplicationA07A04A05
81Design a Logger SystemA03A05A14
82Design a Presence Service APIA14A05-
83Design a Weather SystemA05A14-
84Design a smart alarm systemA09A14A04
85Design a Reservation System for AirbnbA06A08A04
86Design an airline reservation systemA06A08A04
87Design Typeahead SearchA15A05A13
88Design a prompt playgroundA17A18A05
89Design a Server Health Monitoring SystemA05A14A13
90Design a Calendar AppA04A05-
91Design a Parking Lot Management and Rental SystemA06A04A08
92Design a booking waitlist systemA08A14A04
93Design a system to display aggregation of events where multiple robots are continuously generating events in realtimeA05A14A13
94Design a data migration service for GCPA09A18A05
95Design a user referral systemA04A05A13
96Design a Top-K URL System for LinkedIn PostsA13A05-
97Design a signup system for a bankA04A07A05
98Design a Color PickerA17A14-
99Design a Trending Hashtags SystemA13A05A14
100Batched Model RunsA09A05A18
101Design a Social Media Feed Generation SystemA05A14A03
102Design a Scheduler SystemA09A04-
103Design a price notification systemA09A14A05
104Design a MapReduce ShufflerA14A05-
105Design CamelCamelCamelA13A05A09
106Design a project collaboration systemA17A14A04
107Design a Temperature Monitoring SystemA05A14A13
108Design Amazon LockersA06A04A08
109Design a fast food restaurant chain management systemA05A18A15
110Design a Caching System for Multi-Core, Multi-Disk SystemsA05A17-
111Design YouTube Likes SystemA04A05A13
112Design A To-Do List App With Multi-User CollaborationA17A14A04
113Design an end-to-end RAG application with ingestion pipelineA15A05A18
114Design a Quota Manager for LinkedIn APIsA04A05A13
115Design an e-commerce platformA15A04A05
116Design a block storage systemA18A17-
117Design an autocomplete search system for UberA15A05A13
118Design a 3D to 2D rendering serviceA09A05A18
119Design Instacart product catalogueA15A05A18
120Design a system to rollout new versions of a mobile OS to devices worldwideA09A18A05
121Design a machine learning system for detecting prohibited medicine advertisementsA15A05A09
122Design a real-time analytics dashboard for restaurant ordersA05A14A13
123Design a friend activity system for a gaming platformA14A05A03
124Design a Restaurant Booking ServiceA06A08A04
125Design SpotifyA05A18A15
126Design a Top-K Exceptions System from Logs Across ServicesA13A05A14
127Design an Image UploaderA18A05A09
128Design a Facebook post storage and query systemA15A03A05
129Design a sports betting slip sharing feedA05A14A03
130Design an Inventory Management SystemA06A04A05
131Design a Webhook Callback SystemA14A04A09
132Design Google PhotosA18A05A14
133Design RedisA17A18-
134Design a Real-Time Event Message SystemA14A05A13
135Design a password reset systemA04A07A09
136Design a Crypto ExchangeA16A07A04
137Design Car Rental Service SystemA06A04A08
138Design a Google Drive security scannerA15A05A09
139Design a message delivery system between student and teacherA14A03A04
140Design a Tagging System for Atlassian ProductsA19A05-
141Design Wikipedia CrawlerA10A15A05
142Design a Top-K Recommendation SystemA13A05A15
143Design a Database like BitcaskA18A17-
144Design a geofence notification system for vehicle fleetsA14A05A15
145Design a service deployment systemA09A18A04
146Design a Real-time Traffic Monitoring SystemA05A14A15
147Design Paste Bin with MonitoringA18A05A09
148Design a healthcare platformA04A18A05
149Design Facebook PrivacyA04A05A18
150Design expediaA15A06A04
151Design a photo search applicationA15A05A18
152Design a call to text message survey generatorA09A14A04
153Design a Notification System for Marketing CampaignsA09A14A05
154Design YelpA15A05A03
155Design an e-commerce offer subscription systemA09A14A05
156Design a Tesla Supercharger serviceA12A07A04
157Design Data Model for Building Management SystemA05A14A13
158Design a stock ticker tracking systemA13A05A14
159Design an Online BookstoreA15A04A05
160Design an API GatewayA04A05A18
161Design a Dating App Like TinderA12A05A14
162Design a Basic Auth SystemA04A07A05
163Design a transaction processing systemA07A04-
164Design a real-time event classification systemA05A14A15
165Design a data ingestion systemA18A05A09
166Design a system which can resume videosA18A05A14
167Design a machine learning-based content classification systemA15A05A09
168Design a Peer-to-Peer File Sharing SystemA18A14A05
169Design a Unique Identifier System for CustomersA18A04-
170Design an online multiplayer Tic-Tac-ToeA14A04A17
171Design an Elevator Control SystemA12A04-
172Design a Matchmaking Service for Multiplayer GamesA12A13A14
173Design Proximity ServiceA15A14A05
174Design a Health Monitoring System for InfrastructureA05A14A13
175Design AWS LambdaA09A12A04
176Design a global VM monitoring systemA05A14-
177Design a collaboration research document system for Healthcare recordsA17A18A04
178Design PostmanA18A05A17
179Design a distributed task schedulerA09A12A04
180Amazon order historyA05A04-
181Design an Identity and Access Management system for AI agentsA04A18A05
182Design a sequence number generatorA17A18-
183Design a payroll systemA07A04A05
184Design a Distributed Linked List SystemA17A18-
185Design an Auto-Complete Feature for a Store’s Search BarA15A05A13
186Design an ANN index systemA15A05A18
187Design YouTube AnalyticsA05A13A14
188Design a Train Reservation SystemA06A08A04
189Design a Transaction Clearing SystemA07A05A09
190Design a System to Download and Sync Kindle BooksA18A05A14
191Design a file system for write-once mediaA18A17-
192Design Internal App StoreA18A05A04
193Design an Ad Budgeting SystemA07A04A05
194Design a Code Vulnerability Analysis SystemA15A09A05
195Design a Load BalancerA12A05A04
196Design a distributed system for getting the slowest query from Google searchA13A05A14
197Design a Health Monitoring System for Database ServersA05A14A13
198Design a Solution for the Noisy Neighbor ProblemA06A12A04
199Design a Video Converter for YouTubeA09A18A04
200Design a Notification System for RemindersA09A14A04
201Design a Waitlist System for Restaurant ManagementA08A14A04
202Design A Payment System Without InternetA07A18A04
203Design Malicious URL Detection SystemA15A05A14
204Implement Min Heap from ScratchA13--
205Design a Warehouse Management SystemA06A04A05
206Design a Smart City Sensor SystemA05A14A13
207Design Amazon Grocery StoreA06A07A04
208Design a File Downloader LibraryA18A14A05
209Design a Real-Time EC2 Spot Instance Bidding SystemA16A12A04
210Design a Subscribe and Save Feature for an E-commerce WebsiteA09A04A05
211Design an Anti-Phishing SystemA15A05A18
212Design a Pub/Sub SystemA14A03-
213Design a Payment System for Ride-SharingA07A04A12
214Design LLM Checkpointing SystemA18A09A05
215Design a Colocated Shipper Identification SystemA12A15A05
216Design a Proximity Alert System for Apple TagsA14A15A05
217Design a Text-Based Search SystemA15A09A05
218Design a Private Photo Feed AppA18A05A03
219Design Google Search IndexA15A09A05
220Design a Password Manager like KeepassA18A04A07
221Design a historic ‘hot’ posts pageA13A05A03
222Design a Video Moderation SystemA15A05A09
223Design Multi-player FigmaA17A14A18
224Design a Distributed CounterA05A13-
225Design an Automatic Seat Assignment SystemA12A06A05
226Design an AI tutoring platform with RAG based Q&A for assignments and courseworkA15A05A18
227Design a leasing systemA08A09A04
228Design Facebook MarketplaceA15A05A04
229Design Spotify friends listening activitiesA14A05A03
230Design a Risk Assessment Service for Order PurchasesA15A07A05
231Design a Simple File System MetadataA18A17-
232Design Online Block Diagram MakerA17A14A18
233Design a Contacts AppA13A05A14
234Design a Foursquare-like AppA15A05A14
235Design a Video Sharing AppA18A05A14
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