High-Level Design (HLD)

High-Level Design (HLD) outlines the system architecture and overall structure of a software solution. It defines components, modules, data flow, technologies and their interactions. HLD focuses on scalability, performance and reliability, serving as a bridge between requirements and Low-Level Design. It’s essential for planning system-wide decisions.

Top High-Level Design (HLD) Articles

System Design Interview – BIGGEST Mistakes to Avoid

Learn the biggest mistakes to avoid in a system design interview, from unclear requirements to poor trade-off analysis. Includes real-world cases, advanced insights and examples to help you ace your next system design interview.

Top High-Level Design(HLD) Interview Questions 2025

Top High-Level Design(HLD) Interview Questions and answers, HLD QnA, HLD interview preparation

Popular Topics

Query

In databases, a query is a request to retrieve, insert, update or delete data. Written in SQL (Structured Query Language), queries can be simple, like fetching all rows from a table, or complex, involving joins, conditions and aggregations. They are essential for interacting with and managing database information efficiently.

Application Design

Application design is the process of planning and structuring an application’s architecture, user interface, data flow and functionality to meet user and business requirements. It involves decisions on technology stack, design patterns, scalability and security. Good application design ensures performance, maintainability and a seamless user experience across platforms and devices.

Math

math tag that is used for mathematical operations Math is the study of numbers, shapes, patterns and logical relationships. It provides tools for problem-solving, measurement and analysis across science, technology, engineering and daily life. Math includes fields like algebra, geometry, calculus and statistics. It builds critical thinking skills and forms the foundation for computing, algorithms, data science and modern technological advancements.

C# (C-Sharp) is a modern, object-oriented programming language developed by Microsoft for building secure, scalable applications. It runs on the .NET platform and supports features like strong typing, garbage collection, LINQ, async programming and cross-platform development. C# is widely used for web, desktop, game development (Unity), cloud services and enterprise-level software solutions.

Two Pointes

The two-pointer technique is an efficient algorithmic approach that uses two indexes to traverse data structures like arrays or strings. The pointers move toward each other, away from each other or in the same direction to solve problems involving searching, pair finding or window management. It reduces complexity, often turning O(n²) solutions into O(n), making it ideal for optimized problem-solving.

C# Collection

In C#, Collections are classes in the System.Collections and System.Collections.Generic namespaces that store and manage groups of related objects. They include types like List<T>, Dictionary<TKey,TValue>, Queue<T> and Stack<T>. Collections offer dynamic sizing, built-in search, sorting and iteration, making data handling efficient and flexible in C# applications.

Coding Problems

Coding problems are exercises designed to test a programmer’s ability to write logic, solve challenges and apply algorithms or data structures. They help improve problem-solving skills, logical thinking and coding efficiency. Common in interviews and competitive programming, coding problems range from simple tasks to complex algorithmic challenges, preparing developers for real-world software development scenarios.

git branch

git branch is a command used to manage branches within a Git repository. It allows developers to create, list, rename and delete branches. Branches enable parallel development, feature isolation and safe experimentation without affecting the main codebase. Using git branch helps teams organize work efficiently and maintain clean, structured workflows during development.

Language-Concepts

This tag is used to understand a basic part of the language.

DSA

DSA (Data Structures and Algorithms) is a fundamental concept in computer science that focuses on efficiently storing, organizing and processing data. Data structures like arrays, linked lists, stacks and trees manage data, while algorithms provide step-by-step solutions to problems. Mastering DSA is essential for writing optimized, scalable and high-performance code.

Most Popular Tools

Explore our top online tools including a blank page for notes, a QR code generator, word counter and collaborative editor. These free, easy-to-use utilities help you write, analyze, share and organize content faster. Perfect for developers, creators and students to streamline everyday digital tasks efficiently.

Blank Page

Create a blank canvas for your ideas, notes or sketches. Use this tool for rough work and jotting down your thoughts

QR Code Generator

A QR Code Generator is a tool that instantly converts text, URLs or other data into a scannable QR code. Users can create custom QR codes for websites, contact info or messages. It's commonly used for quick access, sharing and printing without needing a backend or complex setup.

Word Counter

Perform various string operations like counting characters, words or letters.

Collaborative Editor

Collab Editor is a powerful, free-to-use online platform that lets you collaborate in real-time. Whether you re working on documents, brainstorming idea, or discussing projects etc