6 min read The difference between candidates who pass and fail is not intelligence or knowledge — it is approach. Candidates who follow […] Read article
6 min read The technical phone screen is your first coding interview — and the highest-rejection stage (60-70% of candidates are eliminated). You […] Read article
5 min read This is the definitive cheat sheet for coding interview patterns. Each pattern is described with: when to recognize it, the […] Read article
6 min read Stripe processes hundreds of billions of dollars annually for millions of merchants, handling the full payment lifecycle from card tokenization […] Read article
6 min read DoorDash processes millions of food delivery orders daily, coordinating three parties: customers, restaurants, and drivers (Dashers). Designing a food delivery […] Read article
6 min read IoT platforms manage millions of connected devices — sensors, cameras, industrial equipment, smart home devices — collecting telemetry data and […] Read article
6 min read Google Calendar manages billions of events for hundreds of millions of users with complex scheduling requirements: recurring events with exceptions, […] Read article
6 min read Beyond the standard DP patterns (knapsack, LCS, linear), advanced DP techniques solve problems that seem intractable at first glance. Bitmask […] Read article
6 min read Reddit is the “front page of the internet” with 50+ million daily active users across 100,000+ active communities (subreddits). Designing […] Read article
7 min read Beyond basic BFS/DFS, advanced graph algorithms solve optimization problems: finding the cheapest path with constraints, detecting negative cycles, computing all-pairs […] Read article