Developer Glossary

The systematic examination of source code by one or more developers to identify bugs, security vulnerabilities, and improve code quality before merging into the main codebase.

The process of analyzing source code without executing it to find potential bugs, security vulnerabilities, and code quality issues.

The implied cost of additional rework caused by choosing an easy (limited) solution now instead of using a better approach that would take longer.

A surface indication in the source code that usually corresponds to a deeper problem in the system. Not a bug itself, but a sign that refactoring may be needed.

The process of restructuring existing code without changing its external behavior to improve readability, reduce complexity, and make it easier to maintain.

The process of running a program that analyzes code for potential errors, bugs, stylistic issues, and suspicious constructs.

Code that is easy to understand, simple to modify, and clearly expresses the intent of the programmer. A philosophy popularized by Robert C. Martin.

Existing code that is difficult to change due to lack of tests, poor documentation, outdated technologies, or original developers no longer available.

A software development principle stating that every piece of knowledge should have a single, authoritative representation in a system.

A design principle that states systems work best when they are kept simple rather than made complex. Simplicity should be a key goal.

An Extreme Programming principle that states programmers should not add functionality until it is actually needed, avoiding speculative features.

Code that is never executed at runtime, including unreachable code, unused functions, and code hidden behind always-false conditions.

Static Application Security Testing — a method of analyzing source code for security vulnerabilities without executing the program.

Dynamic Application Security Testing — a method of testing running applications for security vulnerabilities by simulating attacks.

The Open Worldwide Application Security Project — a nonprofit foundation that works to improve software security through community-led open-source projects.

A regularly updated list of the 10 most critical security risks to web applications, published by OWASP as a standard awareness document for developers.

An attack that forces authenticated users to execute unwanted actions on a web application by tricking them into clicking malicious links or submitting forms.

The process of verifying the identity of a user, device, or system. Answers the question "Who are you?" (contrasted with authorization, which answers "What can you do?").

The practice of securely storing, distributing, and rotating sensitive data like API keys, passwords, database credentials, and certificates.

A security weakness in third-party libraries or packages that an application depends on, which can be exploited to compromise the application.

Automated analysis of code to find security vulnerabilities, bugs, and code quality issues, typically integrated into CI/CD pipelines.

An approach that integrates security practices into every phase of the DevOps pipeline, making security a shared responsibility across development, security, and operations teams.

A code injection technique that exploits security vulnerabilities in an application's database layer by inserting malicious SQL statements into input fields.

A security vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users, potentially stealing session cookies, credentials, or performing actions on behalf of victims.

The use of artificial intelligence and machine learning to automatically analyze code changes and provide feedback on quality, security, and best practices.

The use of automated tools to analyze code and provide feedback without manual human intervention, typically integrated into CI/CD pipelines.

An AI architecture where multiple specialized agents collaborate on complex tasks, each focusing on a specific domain like security, performance, or code quality.

Continuous Integration and Continuous Delivery/Deployment — a set of practices that automate the building, testing, and deployment of code changes.

A set of practices combining software development (Dev) and IT operations (Ops) that aims to shorten the development lifecycle and deliver high-quality software continuously.

GitHub's built-in CI/CD platform that allows you to automate software workflows directly from your repository using YAML configuration files.

A practice of moving testing, quality, and security processes earlier in the software development lifecycle to find and fix issues sooner.

Scripts that run automatically before a git commit is created, used to enforce code quality standards, run linters, and prevent committing problematic code.

A software testing method where individual units or components of code are tested in isolation to verify they work correctly.

A metric that measures the percentage of code executed during testing, indicating how much of the codebase is covered by automated tests.

A testing methodology that validates the entire application workflow from start to finish, simulating real user scenarios including UI, APIs, databases, and external integrations.

A software development practice where tests are written before the actual code, following a cycle of: write a failing test, write minimal code to pass, then refactor.

Testing that verifies different modules or services work correctly together, typically testing interactions between components rather than individual units.

A minimum percentage of code that must be covered by tests, enforced in CI/CD pipelines to ensure new code doesn't decrease overall test coverage.

A technique to evaluate test quality by introducing small changes (mutations) to code and checking if tests detect them. Undetected mutations indicate weak tests.

A method of submitting code changes for review before merging into the main branch. Also known as merge request (MR) in GitLab.

A distributed version control system that tracks changes in source code during software development, enabling multiple developers to work together.

GitLab's term for a pull request — a method of submitting code changes for review before merging into another branch. Functionally identical to GitHub's pull request.

A snapshot of changes in a Git repository that records modifications to files along with a message describing what changed and why.

An independent line of development in Git that allows developers to work on features, fixes, or experiments without affecting the main codebase.

A branching model for Git that defines a strict branching structure designed around project releases, using dedicated branches for features, releases, and hotfixes.

A source-control branching model where developers collaborate on code in a single branch called "trunk" (or main), avoiding long-lived feature branches.

A software metric that measures the number of independent paths through a program's source code, indicating code complexity and testability.

Four key metrics identified by the DevOps Research and Assessment (DORA) team that measure software delivery performance: deployment frequency, lead time for changes, change failure rate, and time to restore service.

Five design principles for object-oriented programming that promote maintainable, flexible, and understandable code: Single Responsibility, Open-Closed, Liskov Substitution, Interface Segregation, and Dependency Inversion.

A quantitative measure of how difficult code is to understand, test, and maintain, based on factors like branching, nesting depth, and dependencies.