What Is a Real-Time Collaborative Whiteboard? A collaborative whiteboard (like Miro, FigJam, or Excalidraw) lets multiple users simultaneously draw, add […]
Shortest Path Algorithms in Interviews Shortest path problems ask: given a graph with weighted or unweighted edges, what is the
What Is a Healthcare Appointment Booking System? A healthcare appointment booking system allows patients to schedule, reschedule, and cancel appointments
What Is a Loyalty and Rewards System? A loyalty program tracks user activity and awards points redeemable for discounts or
What Is a Distributed Lock? A distributed lock ensures that only one node in a cluster executes a critical section
What Is a Typeahead / Search Suggestion System? A typeahead (also called autocomplete or search suggestion) system predicts what a
Advanced Dynamic Programming Patterns Beyond the foundational DP patterns (Fibonacci, 0/1 knapsack, LCS), advanced interviews test state machine DP, interval
What Is an Ad Click Aggregation System? Ad platforms (Google Ads, Meta Ads, Amazon Advertising) must aggregate billions of ad
What Is a Distributed Message Queue? A message queue decouples producers (services that generate work) from consumers (services that process
String Algorithm Patterns in Interviews String problems are ubiquitous in coding interviews. Most string challenges reduce to a small set
What Is a Live Sports Score System? A live sports score system delivers real-time score updates to millions of concurrent
What Is a Cloud File Storage System? A cloud file storage system lets users upload, sync, and share files across
What Is a Web Crawler and Search Indexer? A web crawler systematically downloads web pages. A search indexer processes those
What Is Union-Find? Union-Find (Disjoint Set Union, DSU) is a data structure that tracks a collection of elements partitioned into
What Is an Online Auction System? An online auction system allows sellers to list items and buyers to place competitive
