Funny how some of it is now day-to-day, and other parts of it would be considered extremely weird.
From your perspective, which bits of XP would you consider weird?
TDD is useful in some situations, yep totally. Pair programming is useful in some situations, yes. Continuous integration; yes, much of the time. Frequent feedback; yes, sometimes, for some types of work which doesn't require deep focus...
It just doesn't work as a blanket 'XP' paradigm because you rarely need all these parts all the time, at the same time. IMO, this is why Extreme Programming lacks gumption as a concept. It feels like a bunch of good ideas thrown together. If there was some kind of synergy between those ideas and practices, the concept of XP would be more important.
As it stands today, everyone is implementing maybe 1 or 2 aspects of XP, but almost nobody is implementing ALL of XP... So nobody can claim that they're adhering to XP.
This is not the same as as 'Agile' because with Agile; the vast majority of big companies are implementing maybe 90% of agile practices, with 70% fidelity... This consistency is enough for companies to identify themselves as 'Agile'. I've worked for many companies which implemented ALL of the Agile practices but not one of them actually implemented them exactly as taught in the Agile Manifesto. I think the closest one I worked for was maybe 90% of the way there; they even followed the story point system exactly and used a packet of cards with numbers on them to allow people to vote during Sprint Planning meetings... but anyway, pretty much all the companies/projects I worked for identified themselves 'Agile' because all the practices fit into a single paradigm and there was value in adopting all of them. After a while, it became easier for project managers to just say "Let's switch to Agile" instead of saying "Let's time-box our development work into short increments, with a planning meeting, refinement meeting and retrospective meeting for each 2-week increment."
For production code I do pretty much all of these, always - at least insofar as it is possible (e.g. willing pairing partner).
Im curious to know under which scenarios you think im doing something wrong. Coz I dont think i am.
Clearly AI programming allows you to quickly close feedback loops. I don't think everything needs a comprehensive set of unit tests though.
But if people can go back and understand the core concept of XP (which again is about feedback loops to me) and take advantage of LLM-based agent systems to create those tight closed feedback loops, then that will be an advance for software engineering.
There's a difference in the tests of that era though. Around the xp times, unit tests were for unit of functionality, not per-method.
“Unit tests are small tests, each one exercising a little piece of functionality. The units tested are usually individual methods, but sometimes clusters of methods or even whole objects.”
Extreme Programming Explained: Embrace Change, 2nd Edition (2004) Kent Beck
You said: “Around the xp times, unit tests were not per-method.”
Beck said: “Unit tests are usually individual methods”
Either that or tracing/logging/debugging, but other than specific niches like parsing (of specific bug repros) I think integration tests are generally a lot more bang for the buck.
Anyway, if you want to go down a related-but-unrelated rabbit hole, J.R. Thompson's lecture on the Space Shuttle Main Engines is a good one. You can probably watch it at higher speed to smooth out the many, many "uh"s (believe me, it's bad):
Integrated testing: https://youtu.be/uow6v1EuybE?t=1292
Test to failure: https://youtu.be/uow6v1EuybE?t=3135
https://ocw.mit.edu/courses/16-885j-aircraft-systems-enginee...
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There's this more-modern link but in true modern fashion you can't really link to specific things presumably because it's all javascript muck: https://openlearninglibrary.mit.edu/courses/course-v1:MITx+1...
Actual waterfall looks very much like actual agile, in that it is designed around iteration loops. The primary difference is that waterfall prescribed steps in the iteration process, and agile is just a set of principles in a manifesto.
Edit: reference: https://beza1e1.tuxen.de/waterfall.html
TLDR: the original impetus for waterfall is basically what we call agile today.
Someone copy-pasted a random chart from a paper (one the paper specifically said was too problematic) into a DOD process spec, that turned into a standard because the DOD loves to standardize everything, and big companies all adopted the fundamentally flawed approach and called it waterfall.
This excellent writeup by David Olson gives both the history and the correct understanding; The Myth of the 'Waterfall' SDLC - http://www.bawiki.com/wiki/Waterfall.html
Most of what people are describing here would be unrecognizable to any government program office.
No, Waterfall was not agile, it was the diagram from Royce but not what he recommended from his paper (which tore down that diagram). What Royce added to that diagram (fundamentally, just common sense with feedback loops) was closer to agile, though. Royce himself never called anything Waterfall, but what was termed Waterfall was the bad process he tore apart.
In that case, I don't believe companies follow either. I've never seen anything as principled (in any form) practiced anywhere.
Companies claiming to do Agile were usually doing some rituals and cosplaying as agile. I don't believe I've ever seen a company doing "waterfall" or anything resembling what your link describes either.
They mostly do chaos-driven development.
Then there's the definition - like, is SAFE really agile plus so many other hybrid approaches that have veneer of agile as long as we get all requirements up front and have detailed plan.
It's not that Agile is chaotic because it's cool, it simply (allegedly) surfaces the chaos and uncertainty that was already there. And in my limited experience in consulting, I did build one of these heavily specified LOB software that got canceled near finishing, with all of us laid off and all the effort wasted. This was some CRUD system for an insurance company, by the way; "boring" software by definition.
(To be clear: I'm not arguing Agile truly fixed this, just that what was before had serious enough problems to spark a paradigm change).
Behind the scenes the PMs are making Gantt charts and deciding what's in and what's out and who is going to do it, without the team having any input or really getting to cost it out.
XP and agile generally was supposed to about shortening the communication and iteration gap between customer and maker. I almost never really see that.
I meant in my experience, the methodology most companies I've worked in seems to follow is capital-C Chaotic. Requirements change at the whim of customers or leadership week to week, pivots are frequent and unpredictable, leadership gets fired/quits and the whole plan changes, lots of effort is wasted on stuff that then gets ignored, and customers are sold one thing but delivered another.
I don't believe organizations or companies follow either Agile (any brand of it) or Waterfall. I don't think what they do can be called a methodology at all.
To me, most orgs don't practice any kind of sensible methodology at all. Waterfall implies a rigor they don't have.
It's optimistic because it carries an assumption that you can delineate your development into clear phases with a distinct start and finish. That doesn't work on large projects. You don't spend years designing your new system and then years building it and then years testing it. You commingle each of those, and once you do that, you're not doing Waterfall. You're doing something better, you're using your brain.
Iterative & Incremental, Spiral development, or most ideas out of the Agile movement are better. They incorporate feedback into the project and don't have strongly delineated phases. They don't make 10 year project commitments before they've even written a single requirement. Because these are methods that are realistic.
We didn't get to the moon by Waterfall. The Wright brothers didn't succeed in flight with Waterfall. Linux wasn't developed with Waterfall. Waterfall is a failure for large scale systems.
AI will happily spend the human equivalent of months getting the planning details right before implementation. It won’t by default, to be sure, but if prompted right it will. So you can go into a waterfall implantation plan with significantly better and more thought out plans.
Have you heard of Ada, whose type system does the same thing?
https://tidyfirst.substack.com/p/augmented-coding-beyond-the...
I remember he first posted 2+ years ago, back when people first realized ChatGPT might be useful for coding, that "90% of my skills are now worthless and the remaining 10% are worth 1000x"
https://tidyfirst.substack.com/p/90-of-my-skills-are-now-wor...
This is clearly an AI-generated report based on the code at the time of the generation. I don't see the point of storing them in the history? Especially as this _updated_v2_from_2025 trail of debris.
https://github.com/KentBeck/BPlusTree3/blob/main/rust/docs/C...
https://github.com/KentBeck/BPlusTree3/blob/main/rust/docs/U...
Yet, the most unexpected thing happened this year on my team of 4 senior/staff-level developers:
Instead of "splintering/pairing off with AI" individually even further, we wound up quadrupling (mobbing) full-time on our biggest project to date. That meant four developers, synchronously, plus Claude Code typing for us, working on one task at a time.
That was one of the most fun, laser-focused and weirdly effective way of combining our XP practice with people and AI.
AnimalMuppet•5mo ago
If you pair program with someone else on your team, you both learn what the other is thinking. You both become more familiar with what the code is doing, and why it's doing it.
If you "pair program" with an AI, anything it learned, it forgets as soon as the prompt is closed.
So don't think that's what he's talking about here. He's talking about XP, with humans, just like in the 1990s. There may be some AI in there too, but that's not where the XP part comes from.
imjacobclark•5mo ago
viraptor•5mo ago
Terretta•5mo ago
If that's not what you're doing, you're likely doing it wrong.
> If you pair program with someone else on your team, you both learn what the other is thinking. You both become more familiar with what the code is doing, and why it's doing it.
Yes.
> If you "pair program" with an AI, anything it learned, it forgets as soon as the prompt is closed.
Same with humans, including your future self. So pair on docs.
TL;DR: You should absolutely be XP pair programming with your LLM.
Fulgen•5mo ago
If you want AI slop everywhere, that is.
the_af•5mo ago
Maybe we need a new term, maybe we don't, but it's not pair programming if you're doing it with an LLM.