Nothing went wrong. But, I'm a bit of a skeptic now when some company touts agile to me now. I'm a bit shell-shocked. How could this possibly happen? I'll just list them. Don't worry it's only a few.
- Everyone owns the code
- Mandatory pairing
In theory, this sounds wonderful. It really does and I think it works on a small team of 3-4 dedicated developers. It doesn't scale beyond that. The 3-4 developers must be dedicated to keeping the code clean too. If someone fails to clean up ugly code, then it quickly turns into glue. It turns against you if everyone thinks that everyone else will do the cleanup. There are plenty of negatives to personal code ownership, but the point is to have at least two people as masters of each section. Multiple eyes should see any code commit. But, someone or a pair should own it.
Pairing sounds so good on paper, but it completely takes away the human element. Programmers are introverts by and large. Pairing can wear out some people quickly. I found forced pairing tiresome because not all folks get along. There were some people that I would enjoy pairing with and I learned a lot from. I would always want to pair with them, but other folks it was a constant struggle. I think pairing should be an optional activity that developers should naturally want to do when brain storming or checking in code. I find that code reviews with a pair of eyes who have never seen the code that I am checking is always a good thing. This should be done often. If you think about it, what I am describing is collaboration. Pairing to me as a term basically means one side can turn off. Collaboration is where both sides are equally engaged.
You will notice I didn't list test-driven development above. If anything, XP got that one right. I write tests for everything and stand behind them. I don't see how anyone can stand behind their work without them. I even write tests for my research code. I'm still 100% agile, but I think each practice needs to be tailored to your team. Don't blindly follow the book. If something hurts, don't keep picking at it. You might lose the limb and your project.
This is only the beginning. I plan to write more the subject.