Stacks and queues are fundamental data structures that appear in 15-20% of coding interviews. The stack (LIFO) is essential for […]
Amazon processes millions of orders daily across hundreds of millions of products. Designing an e-commerce platform tests your ability to
Google Maps serves over 1 billion monthly active users with real-time navigation, traffic data, satellite imagery, and location search. Designing
Grid and matrix problems are graph problems in disguise. Each cell is a node; adjacent cells (up, down, left, right)
Slack handles millions of concurrent users across hundreds of thousands of workspaces, delivering messages in real-time while supporting search, file
YouTube is the second largest search engine in the world, serving over 1 billion hours of video daily to 2+
Beyond the classic Gang of Four patterns, several design patterns appear frequently in object-oriented design interviews and production code. This
DNS (Domain Name System) is the internet phone book — translating human-readable domain names into IP addresses. Every web request
When a production system is slow or unresponsive, you need to quickly identify the bottleneck: is it CPU, memory, disk
Counting things at scale — page views, likes, inventory levels, active users — is surprisingly hard in distributed systems. A
The sweep line technique processes events in sorted order along a dimension (typically time or position). It converts 2D problems
Memcached is a high-performance, distributed memory caching system used by Facebook, Twitter, and Wikipedia to reduce database load and accelerate
Topological sort orders vertices in a directed acyclic graph (DAG) such that for every edge (u, v), u appears before
Kubernetes networking is one of the most complex and frequently misunderstood aspects of container orchestration. Every pod gets an IP,
A Content Delivery Network caches content at servers distributed across the globe, serving users from the nearest location. CDNs reduce
