13 posts tagged with "Software Engineering"

The OFFSET clause in SQL skips a specified number of rows in a query result, used alongside LIMIT to retrieve a specific subset. It is the most common approach to pagination in relational databases — but it has important performance limitations at scale.

In SQL, the GROUP BY and DISTINCT clauses play a crucial role in data manipulation, particularly in organizing and summarizing data. Here, we explore the usage, syntax, and working of GROUP BY and DISTINCT with example data, along with insights into how GROUP BY functions behind the scenes.

Introduction to Concurrency​

Concurrency is a fundamental concept in computer science that allows multiple tasks or processes to make progress independently. It is the basis of responsive UIs, high-throughput servers, and efficient use of modern multi-core CPUs.

Concurrency is not the same as parallelism:

• Concurrency — multiple tasks are in progress at the same time (they may take turns on one CPU)
• Parallelism — multiple tasks execute at the exact same instant on multiple CPU cores

An event loop handling 10,000 connections on one thread is concurrent but not parallel. Four threads crunching different sections of a matrix are parallel.

Introduction​

Gin and Echo are Go's two most popular HTTP frameworks. Both are fast, lightweight, and actively maintained — but they make different design choices that matter in practice. This post compares them with real code so you can make an informed decision.

Introduction​

Node.js is often described as a single-threaded environment, yet it is capable of handling millions of concurrent requests. This document explains the reasons behind this design and how Node.js achieves high concurrency through its architecture. Additionally, it provides a detailed overview of the event loop and a full example to illustrate these concepts.

Overview​

WebSockets provide a persistent, full-duplex connection between a client and server, enabling real-time communication without repeated HTTP handshakes. In Go, the github.com/gorilla/websocket package is the standard way to work with WebSockets. This guide walks through building a working WebSocket server and client, handling multiple connections, and keeping connections alive.

Designing a Ride-Sharing App​

Designing a ride-sharing app involves several components and considerations to ensure scalability, performance, and a smooth user experience. Here’s a comprehensive guide to designing a ride-sharing application, including trade-offs and reasoning behind key decisions.

How to Ace the System Design Round​

The system design interview is the most open-ended round in software engineering hiring. There is no single correct answer — you are evaluated on how you structure your thinking, communicate trade-offs, and demonstrate awareness of real-world constraints. This guide covers the framework, key concepts, and worked examples to help you prepare.

Non-blocking design is one of the most important architectural principles in modern software. If you have ever wondered why Node.js can handle thousands of simultaneous connections on a single thread, or why a Go service stays responsive under load, the answer is non-blocking I/O and event-driven execution.

Every program is built around a model of time: operations that run in order, one after another, or operations that run independently and complete whenever they're ready. Understanding synchronous vs. asynchronous execution is fundamental to writing code that performs well under load.