Heap and Priority Queue Interview Patterns
7 min read When to Use a Heap A heap (priority queue) is the right data structure when you need: the minimum or […] Read article
Algorithms
Algorithms
Dynamic Programming Patterns: Tree DP, Digit DP, and Bitmask DP
12 min read Beyond Basic DP Once you’ve mastered 1D/2D tabulation and memoization (Fibonacci, LCS, Knapsack, Coin Change), advanced interview problems require recognizing Read article
System Design
System Design Interview: WebRTC and Real-Time Video Architecture
12 min read WebRTC Architecture Overview WebRTC (Web Real-Time Communication) is an open standard that enables peer-to-peer audio and video in browsers and Read article
System Design
System Design Interview: Social Graph and Friend Recommendations
13 min read Social Graph Requirements A social graph stores relationships between users (friendships, follows, connections) and enables graph queries: friends of friends, Read article
System Design
System Design Interview: Financial Exchange and Matching Engine
11 min read Exchange Architecture Overview A financial exchange matches buy and sell orders — a buyer willing to pay $100 for AAPL Read article
System Design
System Design Interview: Job Scheduler and Task Queue
12 min read Why Task Queues? Task queues decouple work production from work execution. Instead of processing a long-running task synchronously (blocking the Read article
System Design
System Design Interview: Notification System at Scale
12 min read Notification System Requirements A notification system routes messages from producers (application events) to consumers (users) via multiple channels: push notifications Read article
System Design
System Design Interview: Database Indexing and Query Optimization
13 min read Why Indexing Matters Without an index, a SELECT with a WHERE clause requires a sequential scan — reading every row Read article
System Design
System Design Interview: Real-Time Collaborative Editing (Google Docs)
12 min read The Collaboration Problem Real-time collaborative editing lets multiple users edit the same document simultaneously with all changes visible to all Read article
System Design
System Design Interview: API Rate Limiting and Throttling
12 min read Why Rate Limiting? Rate limiting protects services from overload, abuse, and cost explosions. Without it: a single misbehaving client can Read article
Algorithms
Scala Interview Questions: Functional Programming, Case Classes, and Akka (2025)
10 min read Scala Interview Overview Scala is the language of Apache Spark, Kafka (originally), Akka, and many financial systems. Interviews at data Read article
System Design
System Design Interview: Secret Management and PKI (Vault, AWS Secrets Manager)
10 min read Why Secret Management Matters Secrets (database passwords, API keys, TLS certificates, SSH keys) are the crown jewels of any system. Read article
System Design
System Design Interview: Log Aggregation and Observability Pipeline
10 min read Why Log Aggregation? With hundreds of microservices each running multiple replicas, logs are scattered across thousands of containers. Without centralized Read article
Algorithms
Hash Table and HashMap Interview Deep Dive
4 min read Why Hash Tables? Hash tables provide O(1) average-case lookup, insertion, and deletion — making them the most versatile data structure Read article
System Design
System Design Interview: Global Content Delivery and Edge Computing
10 min read Beyond Basic CDN: Edge Computing A CDN (Content Delivery Network) has historically served static assets — images, CSS, JS — Read article