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HelloInterview Questions to Product + Infra Archetype Composition #

This file maps each question in hellointerview_questions.md to:

Legend:

Infra names here are intentionally mechanism-oriented, not product-surface-oriented. The goal is to reduce name overlap with product archetypes such as A09, A17, and A18.

  • Product:
    • 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
  • Infra:
    • I01 = Coordination / Consensus Metadata
    • I02 = Claim / Lease / Exclusive Ownership
    • I03 = Due-Time Release + Claimable Run
    • I04 = Frontier Scan + Claimable Run
    • I05 = Append Log + Consumer Progress
    • I06 = Projection / Index / Search Pipeline
    • I07 = Cache / Origin Projection / Edge Delivery
    • I08 = Traffic Shaping / Admission Control
    • I09 = Sequence / Identifier Generation
    • I10 = Membership / Presence / Registry
    • I11 = Control Plane + Snapshot Distribution
    • I12 = Workflow + External Side Effect
    • I13 = Shared Subject Coordination
    • I14 = Immutable Artifact Namespace + Delivery
    • I15 = Execution Fleet + Worker Substrate
    • I16 = Key-Scoped Mutable State / Replicated KV
    • I17 = Traffic Steering / Request Mediation Plane
    • I18 = Telemetry / Time-Series Pipeline
    • I19 = Replicated Chunk / Block / File Storage Substrate
#QuestionProductInfra
1Design TinyURLA01,A05I14,I06,I07
2Design TicketmasterA06,A08,A07I02,I12,I07
3Design Rate LimiterA05,A04I08,I11
4Design DropboxA18,A05I14,I07
5Design a Distributed CounterA05,A13I09,I06
6Design a Food Delivery App Like DoorDashA12,A04,A14I12,I06,I10
7Design Facebook News FeedA05,A14,A03I06,I07,I05
8Design Webhook ServiceA09,A04,A14I12,I03,I05
9Design YelpA15,A05,A03I06,I07
10Design a Notification SystemA14,A09,A04I12,I03,I06
11Design TypeaheadA15,A05,A13I06,I07
12Design SlackA14,A03,A05I05,I10,I06
13Design UberA12,A04,A14I06,I12,I10
14Design Google DocsA17,A14,A18I13,I10,I14
15Design InstagramA05,A03,A14I06,I07,I05
16Design a Payment SystemA07,A04,A05I12,I05
17Design TinderA12,A05,A14I06,I10
18Design a Key-Value StoreA17,A18I16,I01
19Design WhatsAppA14,A03,A05I05,I10,I06
20Design SpotifyA05,A18,A15I06,I07,I14
21Design a Distributed CacheA05,A17I16,I07
22Design Google DriveA18,A05I14,I06,I07
23Design a Search Autocomplete SystemA15,A05,A13I06,I07
24Design LeetCodeA04,A13,A09I12,I03,I06
25Design AmazonA15,A04,A05I06,I07,I12
26Design a Web CrawlerA10,A15,A05I04,I06,I07
27Design an Ad Click AggregatorA13,A05,A14I05,I06
28Design a Resource Loader in a Game EngineA18,A05I14,I07
29Design Recommender SystemA05,A13I06,I07
30Design a Review and Reward System for Food DeliveryA03,A07,A04I12,I06,I05
31Design a Distributed File SystemA18,A17I19,I14,I01
32Design Facebook Live CommentsA14,A03,A05I05,I06,I10
33Design a ledgerA07,A04I12,I05
34Design a Calendar SystemA04,A05I12,I06
35Design a crossword puzzle serviceA09,A05I03,I04
36Design Netflix Subscription BillingA07,A04,A09I12,I03
37Design Status SearchA15,A05,A03I06,I05
38Design a Review App for Food ItemsA03,A13,A07I06,I12,I05
39Design a Feature Flag ServiceA11,A18,A05I11,I01,I07
40Design a Driver Heatmap SystemA05,A14,A13I06,I05
41Design a cloud storage system like Amazon S3A18,A05I14,I19,I07
42Design a System Metrics Monitoring and Alerting PlatformA05,A14,A09I18,I11,I07
43Design a Ci/Cd PipelineA09,A04,A12I03,I02,I12
44Design a URL ShortenerA01,A05I14,I06,I07
45Design YouTubeA18,A05,A14I14,I06,I07
46Design a Malicious IP Detection SystemA15,A05,A14I17,I06,I11
47Design Online Auction SystemA16,A14,A04I12,I02,I06
48Design TwitterA05,A14,A03I06,I05,I07
49Design a skill-based matchmaking systemA12,A13,A14I06,I02,I10
50Design an analytics dashboard for an AI chat appA05,A13,A14I05,I06,I07
51Design a large model file distribution systemA18,A14,A05I14,I07,I04
52Design an Online Game LeaderboardA13,A05,A14I06,I07
53Design Github ActionsA09,A04,A12I15,I03,I12
54Design a stock trading platformA16,A07,A04I12,I05,I02
55Design Google DocsA17,A14,A18I13,I10,I14
56Design Stock price alerting systemA09,A14,A05I03,I12,I06
57Design Post SearchA15,A05,A03I06,I05
58Design a devbox systemA18,A04,A09I15,I11,I14
59Design a visa payment network system for transaction processingA07,A04I12,I05
60Design a Navigation/Mapping SystemA15,A05,A14I06,I18,I07
61Design a Key-Value StoreA17,A18I16,I01
62Design a Top-K SystemA13,A05I06,I05
63Design SlackA14,A03,A05I05,I10,I06
64Design Vaccine eligibility and booking flowA06,A04,A08I11,I02,I12
65Design a credit card system with approval of paymentsA07,A04,A05I12,I05
66Design a Like/Unlike FeatureA04,A05,A13I06,I05
67Design Top K Songs Display SystemA13,A05I06,I05
68Design CoderPadA17,A14I13,I10
69Design a personal finance trackerA18,A05,A04I14,I06,I12
70Design a Banking SystemA07,A04,A05I12,I05
71Design Asset Price Management SystemA05,A14,A13I05,I06
72Design a Delayed Payment Scheduler ServiceA09,A07,A04I03,I12
73Design a Publisher-Subscriber Message queueA14,A03I05,I12
74Design a 911 Call CenterA12,A04,A14I12,I10,I06
75Design a credit card management and offers systemA07,A05,A04I12,I06,I11
76Design an Ad ServerA16,A05,A14I06,I07,I12
77Design a Facebook posts storage systemA03,A05I05,I06
78Design i18nA11,A18,A05I11,I14
79Design UberA12,A04,A14I06,I12,I10
80Design a Banking ApplicationA07,A04,A05I12,I05
81Design a Logger SystemA03,A05,A14I05,I06
82Design a Presence Service APIA14,A05I10,I07
83Design a Weather SystemA05,A14I06,I07,I05
84Design a smart alarm systemA09,A14,A04I03,I12,I10
85Design a Reservation System for AirbnbA06,A08,A04I02,I12,I07
86Design an airline reservation systemA06,A08,A04I02,I12,I07
87Design Typeahead SearchA15,A05,A13I06,I07
88Design a prompt playgroundA17,A18,A05I13,I14,I07
89Design a Server Health Monitoring SystemA05,A14,A13I18,I11,I07
90Design a Calendar AppA04,A05I12,I06
91Design a Parking Lot Management and Rental SystemA06,A04,A08I02,I12,I07
92Design a booking waitlist systemA08,A14,A04I03,I12,I07
93Design a system to display aggregation of events where multiple robots are continuously generating events in realtimeA05,A14,A13I05,I06
94Design a data migration service for GCPA09,A18,A05I04,I14,I11
95Design a user referral systemA04,A05,A13I12,I06
96Design a Top-K URL System for LinkedIn PostsA13,A05I06,I05
97Design a signup system for a bankA04,A07,A05I12,I11,I05
98Design a Color PickerA17,A14I13,I10
99Design a Trending Hashtags SystemA13,A05,A14I05,I06,I18
100Batched Model RunsA09,A05,A18I15,I03,I14
101Design a Social Media Feed Generation SystemA05,A14,A03I06,I07,I05
102Design a Scheduler SystemA09,A04I03,I02,I12
103Design a price notification systemA09,A14,A05I03,I12,I06
104Design a MapReduce ShufflerA14,A05I05,I04
105Design CamelCamelCamelA13,A05,A09I04,I06,I07
106Design a project collaboration systemA17,A14,A04I13,I10,I12
107Design a Temperature Monitoring SystemA05,A14,A13I18,I11,I07
108Design Amazon LockersA06,A04,A08I02,I12,I11
109Design a fast food restaurant chain management systemA05,A18,A15I11,I06,I14
110Design a Caching System for Multi-Core, Multi-Disk SystemsA05,A17I16,I07,I01
111Design YouTube Likes SystemA04,A05,A13I05,I06
112Design A To-Do List App With Multi-User CollaborationA17,A14,A04I13,I10,I12
113Design an end-to-end RAG application with ingestion pipelineA15,A05,A18I06,I04,I14
114Design a Quota Manager for LinkedIn APIsA04,A05I08,I11
115Design an e-commerce platformA15,A04,A05I06,I07,I12
116Design a block storage systemA18,A17I19,I15,I01
117Design an autocomplete search system for UberA15,A05,A13I06,I07
118Design a 3D to 2D rendering serviceA09,A05,A18I15,I03,I14
119Design Instacart product catalogueA15,A05,A18I06,I14,I07
120Design a system to rollout new versions of a mobile OS to devices worldwideA09,A18,A05I11,I03,I14
121Design a machine learning system for detecting prohibited medicine advertisementsA15,A05,A09I04,I06,I12
122Design a real-time analytics dashboard for restaurant ordersA05,A14,A13I05,I06,I07
123Design a friend activity system for a gaming platformA14,A05,A03I05,I06,I10
124Design a Restaurant Booking ServiceA06,A08,A04I02,I12,I07
125Design SpotifyA05,A18,A15I06,I07,I14
126Design a Top-K Exceptions System from Logs Across ServicesA13,A05,A14I05,I06
127Design an Image UploaderA18,A05,A09I14,I04,I06
128Design a Facebook post storage and query systemA15,A03,A05I06,I05
129Design a sports betting slip sharing feedA05,A14,A03I06,I05,I07
130Design an Inventory Management SystemA06,A04,A05I12,I06,I11
131Design a Webhook Callback SystemA14,A04,A09I12,I05,I03
132Design Google PhotosA18,A05,A14I14,I06,I07
133Design RedisA17,A18I16,I07,I05
134Design a Real-Time Event Message SystemA14,A05,A13I05,I06
135Design a password reset systemA04,A07,A09I12,I03,I11
136Design a Crypto ExchangeA16,A07,A04I12,I05,I02
137Design Car Rental Service SystemA06,A04,A08I02,I12,I07
138Design a Google Drive security scannerA15,A05,A09I04,I06,I14
139Design a message delivery system between student and teacherA14,A03,A04I05,I10,I12
140Design a Tagging System for Atlassian ProductsA19,A05I11,I06
141Design Wikipedia CrawlerA10,A15,A05I04,I06,I07
142Design a Top-K Recommendation SystemA13,A05,A15I06,I07
143Design a Database like BitcaskA18,A17I16,I05,I19
144Design a geofence notification system for vehicle fleetsA14,A05,A15I05,I06,I12
145Design a service deployment systemA09,A18,A04I11,I03,I14
146Design a Real-time Traffic Monitoring SystemA05,A14,A15I18,I06,I07
147Design Paste Bin with MonitoringA18,A05,A09I14,I06,I12
148Design a healthcare platformA04,A18,A05I11,I14,I06
149Design Facebook PrivacyA04,A05,A18I11,I06,I14
150Design expediaA15,A06,A04I06,I07,I12
151Design a photo search applicationA15,A05,A18I06,I14,I07
152Design a call to text message survey generatorA09,A14,A04I03,I12,I05
153Design a Notification System for Marketing CampaignsA09,A14,A05I03,I12,I06
154Design YelpA15,A05,A03I06,I07
155Design an e-commerce offer subscription systemA09,A14,A05I03,I12,I06
156Design a Tesla Supercharger serviceA12,A07,A04I12,I10,I06
157Design Data Model for Building Management SystemA05,A14,A13I05,I06,I10
158Design a stock ticker tracking systemA13,A05,A14I05,I06
159Design an Online BookstoreA15,A04,A05I06,I07,I12
160Design an API GatewayA04,A05,A18I17,I08,I11
161Design a Dating App Like TinderA12,A05,A14I06,I10,I07
162Design a Basic Auth SystemA04,A07,A05I11,I12,I07
163Design a transaction processing systemA07,A04I12,I05
164Design a real-time event classification systemA05,A14,A15I05,I06,I11
165Design a data ingestion systemA18,A05,A09I04,I05,I14
166Design a system which can resume videosA18,A05,A14I14,I06,I10
167Design a machine learning-based content classification systemA15,A05,A09I04,I06,I12
168Design a Peer-to-Peer File Sharing SystemA18,A14,A05I14,I07,I04
169Design a Unique Identifier System for CustomersA18,A04I09,I01
170Design an online multiplayer Tic-Tac-ToeA14,A04,A17I13,I10,I12
171Design an Elevator Control SystemA12,A04I12,I02,I06
172Design a Matchmaking Service for Multiplayer GamesA12,A13,A14I06,I02,I10
173Design Proximity ServiceA15,A14,A05I06,I10,I07
174Design a Health Monitoring System for InfrastructureA05,A14,A13I18,I11,I07
175Design AWS LambdaA09,A12,A04I15,I03,I11
176Design a global VM monitoring systemA05,A14I18,I11,I07
177Design a collaboration research document system for Healthcare recordsA17,A18,A04I13,I14,I11
178Design PostmanA18,A05,A17I11,I14,I07
179Design a distributed task schedulerA09,A12,A04I03,I15,I11
180Amazon order historyA05,A04I06,I07
181Design an Identity and Access Management system for AI agentsA04,A18,A05I11,I01,I07
182Design a sequence number generatorA17,A18I09,I01
183Design a payroll systemA07,A04,A05I12,I11,I06
184Design a Distributed Linked List SystemA17,A18I01,I14
185Design an Auto-Complete Feature for a Store’s Search BarA15,A05,A13I06,I07
186Design an ANN index systemA15,A05,A18I06,I07,I14
187Design YouTube AnalyticsA05,A13,A14I05,I06,I18
188Design a Train Reservation SystemA06,A08,A04I02,I12,I07
189Design a Transaction Clearing SystemA07,A05,A09I12,I05,I06
190Design a System to Download and Sync Kindle BooksA18,A05,A14I14,I06,I07
191Design a file system for write-once mediaA18,A17I19,I14,I01
192Design Internal App StoreA18,A05,A04I11,I14,I07
193Design an Ad Budgeting SystemA07,A04,A05I08,I12,I06
194Design a Code Vulnerability Analysis SystemA15,A09,A05I15,I06,I12
195Design a Load BalancerA12,A05,A04I17,I11,I08
196Design a distributed system for getting the slowest query from Google searchA13,A05,A14I18,I05,I06
197Design a Health Monitoring System for Database ServersA05,A14,A13I18,I11,I07
198Design a Solution for the Noisy Neighbor ProblemA06,A12,A04I11,I02,I06
199Design a Video Converter for YouTubeA09,A18,A04I15,I14,I12
200Design a Notification System for RemindersA09,A14,A04I03,I12,I06
201Design a Waitlist System for Restaurant ManagementA08,A14,A04I03,I12,I07
202Design A Payment System Without InternetA07,A18,A04I12,I14,I01
203Design Malicious URL Detection SystemA15,A05,A14I06,I05,I07
204Implement Min Heap from ScratchA13I09
205Design a Warehouse Management SystemA06,A04,A05I12,I06,I11
206Design a Smart City Sensor SystemA05,A14,A13I18,I05,I06
207Design Amazon Grocery StoreA06,A07,A04I12,I02,I06
208Design a File Downloader LibraryA18,A14,A05I14,I07,I10
209Design a Real-Time EC2 Spot Instance Bidding SystemA16,A12,A04I12,I02,I11
210Design a Subscribe and Save Feature for an E-commerce WebsiteA09,A04,A05I03,I12,I06
211Design an Anti-Phishing SystemA15,A05,A18I17,I11,I06
212Design a Pub/Sub SystemA14,A03I05,I10
213Design a Payment System for Ride-SharingA07,A04,A12I12,I05,I06
214Design LLM Checkpointing SystemA18,A09,A05I15,I14,I07
215Design a Colocated Shipper Identification SystemA12,A15,A05I06,I11,I07
216Design a Proximity Alert System for Apple TagsA14,A15,A05I10,I06,I12
217Design a Text-Based Search SystemA15,A09,A05I04,I06,I07
218Design a Private Photo Feed AppA18,A05,A03I14,I06,I07
219Design Google Search IndexA15,A09,A05I04,I06,I07
220Design a Password Manager like KeepassA18,A04,A07I14,I11,I12
221Design a historic ‘hot’ posts pageA13,A05,A03I05,I06,I07
222Design a Video Moderation SystemA15,A05,A09I04,I06,I12
223Design Multi-player FigmaA17,A14,A18I13,I10,I14
224Design a Distributed CounterA05,A13I09,I06
225Design an Automatic Seat Assignment SystemA12,A06,A05I06,I11,I02
226Design an AI tutoring platform with RAG based Q&A for assignments and courseworkA15,A05,A18I06,I14,I07
227Design a leasing systemA08,A09,A04I02,I03,I12
228Design Facebook MarketplaceA15,A05,A04I06,I07,I12
229Design Spotify friends listening activitiesA14,A05,A03I05,I10,I06
230Design a Risk Assessment Service for Order PurchasesA15,A07,A05I06,I12,I05
231Design a Simple File System MetadataA18,A17I19,I01
232Design Online Block Diagram MakerA17,A14,A18I13,I10,I14
233Design a Contacts AppA13,A05,A14I06,I10,I07
234Design a Foursquare-like AppA15,A05,A14I06,I07,I10
235Design a Video Sharing AppA18,A05,A14I14,I06,I07
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