Extreme Programming (XP)
Extreme Programming is characterised by running through all disciplines of classical software development — requirements analysis, design, implementation, and testing — in short, repeated cycles. This makes the overall methodology lightweight and adaptive.
Extreme Programming (XP) is not just a methodology — it is a discipline. Coined by Kent Beck in the late 1990s, XP takes well-established software engineering practices and, as the name suggests, applies them to an extreme degree. If testing is good, we test everything. If feedback is valuable, we seek it continuously. If integration catches bugs, we integrate every few hours.
At Parlant GmbH, XP is the foundation of how we work. Not as a dogmatic rulebook, but as a set of practices that we have found to consistently produce better software.
Core Practices We Follow
Test-Driven Development (TDD) — Every feature begins with a failing test. Only then do we write the code that makes it pass. This is not optional — it is how we design. More on TDD →
Pair Programming — Two developers work on the same problem simultaneously. One writes code, the other reviews in real time. The result is fewer defects, better knowledge sharing, and higher code quality. This is not a luxury — it is an investment that pays off through reduced debugging and maintenance time.
Continuous Integration — Every change is integrated into the main branch multiple times a day. Automated tests run on every commit. If something breaks, it is caught within minutes — not days.
Small Releases — We deliver in small, frequent increments. Each release is a working, tested version of the software. This keeps feedback loops short and reduces the risk of large, untested changes.
Collective Code Ownership — Any developer on the team can modify any part of the codebase. This prevents knowledge silos and ensures that the system is not dependent on any single person.
Simple Design — We build the simplest solution that solves the current problem. Not the most flexible, not the most abstract — the simplest. Complexity is added only when it is justified by concrete requirements.
Refactoring — Code is continuously improved without changing its behaviour. This keeps the codebase clean, understandable, and ready for future changes. Refactoring is not a phase — it is part of every development cycle.
Why XP Works for Us
XP is particularly effective in environments that match our typical engagements:
- Uncertain or evolving requirements — XP is designed for change. Short cycles and continuous feedback make it easy to adapt.
- Small to medium teams — XP practices scale well in teams of 2–8 developers. For larger teams, we apply the underlying principles while adjusting the specific practices.
- High quality expectations — The combination of TDD, pair programming, and continuous integration produces software that is demonstrably well-tested and well-designed.
XP at Parlant
We do not adopt XP selectively. The practices reinforce each other: TDD makes refactoring safe, continuous integration makes small releases possible, and pair programming catches the defects that even good tests might miss. Removing one practice weakens the others.
This is the discipline that underpins our pragmatic approach to software development — and it shows in the reliability and maintainability of the systems we deliver.