System Design: Distributed Tracing System (Jaeger/Zipkin-style) Distributed tracing tracks a single request as it propagates through microservices, allowing engineers to […]

Low-Level Design: Online Code Judge (LeetCode-style) The online code judge LLD involves designing a system that accepts code submissions, compiles

Low-Level Design: Splitwise (Expense Sharing App) The Splitwise LLD asks you to model a shared expense tracker where users add

Low-Level Design: Pub/Sub Message Broker A Pub/Sub (Publish-Subscribe) message broker decouples producers from consumers through named topics. Producers publish events;

Low-Level Design: Food Delivery App (DoorDash / Uber Eats) The food delivery app LLD question asks you to model the

Low-Level Design: Task Scheduler The Task Scheduler is a recurring LLD interview question at companies like Google, Meta, Airbnb, and

Consistent Hashing: System Design Deep Dive Consistent hashing is a distributed hashing scheme that minimises key remapping when nodes are

Problem Statement Design a social network graph system like LinkedIn’s connection model or Facebook’s friends graph. Users can send friend

Problem Statement Design a stock trading order book system. Traders submit buy and sell orders at specific prices and quantities.

Problem Statement Design an online auction system like eBay. Sellers list items with a starting price, auction duration, and reserve

Problem Statement Design a search autocomplete (typeahead) system like Google Search suggestions or Amazon product search. As a user types,

Problem Statement Design the core backend of a ride-sharing app like Uber or Lyft. A rider requests a trip with