6 min read What is Topological Sort? A topological sort of a Directed Acyclic Graph (DAG) is a linear ordering of vertices such […] Read article
7 min read Core Requirements An inventory management system tracks the quantity of products across one or more warehouses, coordinates stock reservations during […] Read article
6 min read BFS Fundamentals BFS (Breadth-First Search) explores a graph level by level, visiting all nodes at distance 1 before distance 2, […] Read article
7 min read Core Requirements A digital wallet holds a user’s balance and enables peer-to-peer transfers. Key operations: add money (top-up from a […] Read article
6 min read When Math Problems Appear Math interview problems test number theory, combinatorics, and modular arithmetic. Common patterns: prime checking and sieve, […] Read article
7 min read Core Entities Restaurant: restaurant_id, name, address, lat, lng, cuisine_type, rating, is_open, prep_time_minutes (average). MenuItem: item_id, restaurant_id, name, description, price, category, […] Read article
6 min read Core Entities Hotel: hotel_id, name, address, city, star_rating, amenities (JSON), check_in_time, check_out_time. RoomType: room_type_id, hotel_id, name (STANDARD, DELUXE, SUITE), max_occupancy, […] Read article
6 min read Tree DP Pattern Many tree problems require computing an answer that depends on both subtrees. The key pattern: define a […] Read article
7 min read Core Entities Flight: flight_id, airline, flight_number, origin_airport, destination_airport, departure_time, arrival_time, aircraft_type, status (SCHEDULED, BOARDING, DEPARTED, ARRIVED, CANCELLED, DELAYED). Seat: seat_id, […] Read article
6 min read The Three Pillars of Observability Observability lets engineers understand the internal state of a system from its external outputs. Three […] Read article