Array and string problems are the bread and butter of coding interviews, appearing in over 40% of questions. The key […]
PostgreSQL is the most popular open-source relational database, powering applications from startups to enterprises. Understanding its internals — how MVCC
A centralized logging system collects, indexes, and makes searchable the logs from hundreds or thousands of microservices. Without it, debugging
Heaps (priority queues) are the go-to data structure for problems involving the K-th largest/smallest element, merging sorted sequences, and scheduling
In a microservices architecture, maintaining data consistency across services is the hardest challenge. A single business operation (placing an order)
Search autocomplete (typeahead) suggests query completions as the user types, reducing keystrokes and guiding users toward popular or relevant searches.
Prefix sum is one of the most versatile techniques in competitive programming and coding interviews. It transforms O(N) range queries
Database connection pooling is a critical optimization for any application that uses a relational database. Without pooling, every database query
Distributed file systems store files across multiple machines, providing storage capacity and throughput far beyond a single server. HDFS (Hadoop
Sorting is the most fundamental algorithmic operation — it appears directly in interview questions and as a building block for
An API gateway is the single entry point for all client requests in a microservices architecture. It handles cross-cutting concerns
Netflix serves over 200 million subscribers across 190 countries, streaming billions of hours of video per month. Designing a video
Greedy algorithms make the locally optimal choice at each step, hoping to find the global optimum. Unlike dynamic programming which
Data warehouses are purpose-built for analytical queries — aggregations, joins, and scans across billions of rows that would bring an
The CAP theorem is the most cited theorem in distributed systems — and the most misunderstood. It states that a
