Content Delivery Network (CDN) System Design
What a CDN Does A Content Delivery Network serves content from geographically close edge nodes, dramatically reducing latency. A request […]
Design, System Design
Design, System Design
Message Queue System Low-Level Design
Message queues like Kafka, RabbitMQ, and SQS show up in both system design and low-level design interviews. Understanding the internals
Algorithms, Coding Interview Questions, Linked List
Linked List Interview Patterns
Linked list problems trip up candidates because pointer manipulation is easy to mess up under pressure. These patterns cover every
Algorithms, Coding Interview Questions, Data Structures
Sorting Algorithm Interview Patterns
Sorting problems appear constantly in interviews – not just “implement merge sort” but as tools to simplify harder problems. Master
Design, System Design
Payment System Low-Level Design
Payment State Machine A payment must move through well-defined states. Never allow arbitrary transitions or skipped states. INITIATED -> PROCESSING
Algorithms, Coding Interview Questions, Greedy
Greedy Algorithm Interview Patterns
When Greedy Works: The Exchange Argument Greedy algorithms make the locally optimal choice at each step. They are provably correct
Design, System Design
URL Shortener System Low-Level Design
Requirements Functional requirements for a URL shortener: Create a short URL from a long original URL Redirect users from the
Design, System Design
Distributed Cache System Low-Level Design
Caching is the single highest-leverage optimization in most systems. A well-designed cache can cut database load by 90% and reduce
Algorithms, Coding Interview Questions, String, String Manipulation
String Interview Patterns
Strings appear in roughly 25-30% of coding interviews. Unlike arrays or trees, string problems have a concentrated set of patterns
Design, System Design
Search Autocomplete System Low-Level Design
Search autocomplete is one of the most latency-sensitive features in any product. Users expect suggestions within 100ms of each keystroke.
Algorithms, Coding Interview Questions
Interval Interview Patterns
Interval problems are a reliable interview topic at every level. The core patterns repeat across dozens of problems – learn
Design, System Design
Rate Limiter System Low-Level Design
Rate limiting is a core system design topic. This guide covers every major algorithm, their trade-offs, and Redis implementation patterns
Algorithms, Coding Interview Questions, Trie
Trie Interview Patterns
Trie (prefix tree) problems appear frequently in coding interviews. This guide covers the core patterns with Python implementations you can
Algorithms, Coding Interview Questions, Graphs, Shortest Path
Graph Shortest Path Interview Patterns
Shortest path problems appear in nearly every graph interview. The key skill is recognizing which algorithm applies to the given
Design, System Design
User Authentication System Low-Level Design
Authentication is one of the most common low-level design questions in system design interviews, and one of the most commonly