Extreme Programming

Extreme Programming (XP) is an agile software development approach that emphasizes frequent releases, close collaboration, and technical excellence. It aims to improve software quality and responsiveness to changing requirements through a set of engineering practices and team values.

XP was created in the context of software teams working in fast-changing environments. It focuses on what makes software development successful and applies those practices intensively and consistently.

Key practices in XP include:

• Test-Driven Development (TDD): Writing automated tests before writing the code that needs to pass them.
• Pair Programming: Two developers work together at one computer, sharing design decisions and reviewing code in real-time.
• Continuous Integration: Teams integrate and test code frequently to detect issues early.
• Refactoring: Improving the internal structure of code without changing its behavior, to keep it clean and adaptable.
• Simple Design: Building only what is needed now, avoiding over-engineering.
• Collective Code Ownership: Anyone on the team can improve any part of the code at any time.
• Sustainable Pace: Teams avoid long hours to maintain energy and quality over time.
• Small Releases: Delivering working software to users frequently to gather feedback and reduce risk.
• On-Site Customer: Having direct access to someone who understands the business needs and can provide fast feedback.

XP also encourages strong team collaboration and shared responsibility for delivering high-quality software. Many of its practices can and should be combined with Scrum, especially where Scrum leaves room for teams to choose their technical practices.

XP remains one of the most influential agile approaches, especially for teams that want to improve their engineering discipline.