Git branches are lightweight names that point to commits. Think of them as parallel timelines: you can try ideas on a branch without touching main, then merge back when you’re happy...
When managing software projects, organizations often need to choose between two distinct codebase structuring strategies: monorepos and multirepos. This decision isn’t just about where code lives—it affects collaboration, tooling, versioning, and even deployment practices. When you’re starting out o...
In Git, you might accumulate multiple small commits over the course of developing a new feature, fixing small bugs, or refactoring code. While these incremental commits are crucial during active development, they can clutter the project history in the long term. This clutter becomes especially evide...
Working with files on Unix-based systems often involves managing multiple files and directories, especially when it comes to storage or transferring data. Tools like tar and gzip are invaluable for packaging and compressing files efficiently. Understanding how to use these commands can simplify task...
We will discuss various tools that can be used on Linux systems for tasks such as taking screenshots, recording screens, preparing bootable sticks, and detecting malware. It provides brief explanations of each tool and includes installation and usage instructions...
Cron is a powerful utility in Unix-like operating systems that automates the execution of scripts or commands at specified times, dates, or intervals. It is used for tasks such as system maintenance, backups, updates, and more...
Inodes are critical as they store essential metadata about files, such as permissions and locations, allowing efficient file system management. Hard links are important because they let multiple file names point to the same inode, saving disk space by avoiding data duplication. Symlinks provide flex...
We will now delve deeply into the Linux kernel to understand its role in the operating system, where it resides on your system, and how kernel modules function. We will also explore how to download and examine the Linux kernel source code, and discuss the various configuration options available with...
In any operating system, a process is the fundamental unit of execution—a live instance of a program. Beyond its executable code (the text segment), a process encompasses its dynamic state: the program counter, CPU registers, call stack, heap, and other variable storage. To manage and schedule these...
One of the fundamental skills is to navigate and manage files and directories effectively. Here, we focus on the crucial concepts that will facilitate your work within the file system...
File permissions are crucial in any Unix-like operating systems, including Linux, which employ several mechanisms for controlling access to files and directories. These mechanisms include standard permissions, special permissions, and access control lists (ACLs)...
The Dynamic Window Manager (DWM) is a minimal, lightweight, and highly efficient tiling window manager designed to help you manage application windows in a clean and distraction-free manner. Instead of overlapping windows as seen in traditional window managers, DWM organizes windows in a tiled layou...
Linux is a versatile and powerful open-source operating system that forms the backbone of countless technological infrastructures, from servers and desktops to mobile devices and embedded systems. Known for its stability, security, and flexibility, Linux provides a robust platform that can be custom...
In Unix, files and filesystems are important components of the operating system's structure. A file is a collection of data stored on disk, which can include anything from text documents and images to executable programs. Files are organized within directories in a hierarchical structure, allowing f...
We'll explore the inner workings of the Linux kernel, focusing on how it loads and executes binaries. We'll dive into the execve system call, build a custom kernel, and use debugging tools to see the execution process in action. Whether you're a seasoned developer or just curious about operating sys...
Input redirection (<) allows a command to read from a file, while output redirection (>) sends a command's output to a file. Streams like stdin, stdout, and stderr control the flow of data between commands and the system, where stdin is the input, stdout is the standard output, and stderr is the err...
Managing and monitoring disk usage is necessary for server maintenance, allowing administrators to identify disk space shortages caused by large log files, such as Apache or system logs, and malfunctioning applications that generate excessive data. Tools like df provide quick overviews of available ...
A firewall is like a guard for your computer. It keeps your computer safe from others who shouldn't use it. It checks the information going in and out and follows safety rules. In Linux, there are several utilities to manage your firewall, including iptables, ufw, and firewalld...
SSH, SFTP, and SCP are network protocols that provide secure data communication and file transfer over insecure networks. Here's a brief overview of each...
Debian and Ubuntu are popular Linux distributions for home users. These distributions and their derivatives use the Advanced Package Tool (APT). Other distributions use alternative package managers, like DNF, YUM, Pacman, which have unique functionalities and syntax...
Netlify allows you to easily deploy and manage static websites. A Python-based static site generator like Pelican, MkDocs, or Frozen-Flask produces HTML files that Netlify serves through its global CDN...
Digital Ocean provides cloud-based virtual machines called Droplets that let you deploy and manage CentOS servers. The overall flow looks like this...
Message queues enable asynchronous, decoupled communication in distributed systems by allowing publishers to send messages to a queue that consumers process independently, typically in first-in, first-out order. This approach reduces direct dependencies between services, enhances reliability and sca...
Operational Transform is a foundational technique in distributed systems that enables real-time collaborative editing of shared documents. Originally proposed by Ellis and Gibbs in 1989, OT allows multiple users to concurrently modify the same document while preserving consistency across all partici...
Linearizability is a consistency model that makes a distributed system appear as if there is only a single copy of the data, and every operation takes effect atomically at some point between its invocation and its response. Even when data is replicated across multiple nodes, a linearizable system gu...
Concurrent writes happen when two or more clients write to the same key in a database at the same time, each unaware of the other's write. In replicated systems, these writes may arrive at different replicas in different orders, causing the replicas to diverge and hold conflicting values. Without a ...
The Gossip Protocol is a peer-to-peer communication technique in distributed systems where nodes share information by randomly selecting partners and exchanging state, much like how rumors spread through a social network. It is especially useful in large clusters where nodes frequently join or leave...
Caching is a technique used to speed up data retrieval by placing frequently accessed or computationally heavy information closer to the application or the end user. Below is an expanded set of notes on caching, presented with ASCII diagrams and bullet points that emphasize key considerations. Each ...
A Content Delivery Network (CDN) is a geographically distributed system of servers that deliver web assets such as images, videos, stylesheets, and scripts to users based on their proximity to the nearest server. By placing cached copies of content at strategic locations around the world, CDNs drast...
Covariance is a fundamental statistical measure that quantifies the degree to which two random variables change together. It indicates the direction of the linear relationship between variables...
Correlation is a statistical measure that quantifies the strength and direction of the linear relationship between two variables. It is a fundamental concept in statistics, enabling researchers and analysts to understand how one variable may predict or relate to another. The most commonly used corre...
Logistic regression is a statistical method used for modeling the probability of a binary outcome based on one or more predictor variables. It is widely used in various fields such as medicine, social sciences, and machine learning for classification problems where the dependent variable is dichotom...
Simple linear regression is a statistical method used to model the relationship between a single dependent variable and one independent variable. It aims to find the best-fitting straight line through the data points, which can be used to predict the dependent variable based on the independent varia...
When conducting multiple hypothesis tests simultaneously, the likelihood of committing at least one Type I error (falsely rejecting a true null hypothesis) increases. This increase is due to the problem known as the "multiple comparisons problem" or the "look-elsewhere effect". The methods to addres...
Hypothesis testing is a core concept in statistics that allows researchers to evaluate assumptions about a population by examining sample data. In this process, we start with a null hypothesis, denoted by $H_0$, which represents a baseline or default position, and an alternative hypothesis, $H_a$, w...