Divide and Conquer Interview Patterns: Merge Sort, Quick Select, Master Theorem
7 min read The Divide and Conquer Paradigm Divide and conquer solves problems by: (1) Divide — split the problem into smaller subproblems […] Read article
Algorithms
Algorithms
Monotonic Stack Interview Patterns: Next Greater, Histograms, Stock Span
7 min read What Is a Monotonic Stack? A monotonic stack is a stack that maintains its elements in either monotonically increasing or Read article
System Design
System Design Interview: Distributed Message Queue (Kafka / SQS)
7 min read Why Message Queues? A message queue decouples producers (services that generate events) from consumers (services that process them), enabling async Read article
Algorithms
Union-Find (Disjoint Set Union) Interview Patterns
6 min read What Is Union-Find? Union-Find (also called Disjoint Set Union or DSU) is a data structure that efficiently tracks which elements Read article
Algorithms
Binary Tree Interview Patterns: Traversal, DFS, BFS, and Classic Problems
7 min read Tree Traversal Fundamentals Binary tree problems appear in nearly every technical interview. The foundation is traversal order, which determines which Read article
System Design
System Design Interview: Real-Time Chat System (WhatsApp / Slack)
7 min read Core Requirements A real-time chat system must: deliver messages in under 100ms end-to-end, support 1:1 and group chats, handle offline Read article
System Design
System Design Interview: File Storage and Sync Service (Dropbox)
7 min read Designing a file storage and sync service like Dropbox combines chunked file storage, delta sync, conflict resolution, and offline-first architecture. Read article
Algorithms
String DP Interview Patterns: LCS, Edit Distance, Palindrome DP
8 min read String dynamic programming problems — longest common subsequence, edit distance, palindromic subsequences — appear frequently in senior engineering interviews. These Read article
System Design
System Design Interview: Twitter / Social Media Feed Architecture
5 min read Designing a social media feed like Twitter is one of the most comprehensive system design problems. The core challenge: how Read article
System Design
System Design Interview: Hotel and Airbnb Booking System
7 min read Designing a hotel or home-sharing booking system like Airbnb is a comprehensive system design problem that combines availability calendars, concurrent Read article
System Design
System Design Interview: Video Streaming Platform (Netflix/YouTube)
7 min read Designing a video streaming platform like Netflix or YouTube is one of the most comprehensive system design challenges, combining video Read article
Algorithms
Dynamic Programming Knapsack Patterns: 0/1, Unbounded, Subset Sum
7 min read Knapsack problems are the most important dynamic programming pattern class. Mastering 0/1 knapsack, unbounded knapsack, and their variants (subset sum, Read article
System Design
System Design Interview: Email Service at Scale (SendGrid/Gmail)
6 min read Designing a transactional email service (like SendGrid or AWS SES) or an email client (like Gmail) involves deep distributed systems Read article
System Design
System Design Interview: Autocomplete and Typeahead Service
6 min read Designing an autocomplete (typeahead) service is one of the most common system design interview questions, frequently asked at Google, Meta, Read article
System Design
System Design Interview: Ticketing and Seat Reservation System
7 min read Designing a ticketing system like Ticketmaster or a seat reservation system for movies/concerts tests your understanding of concurrency, distributed locking, Read article