before you ran it. Um, so and that brings me then to a different tweet from France Chalet uh where he says, "Agentic coding is a form of machine learning. Generated code is best treated as a blackbox artifact whose behavior and generalization should be managed via empirical evaluation like with any ML model." Um, and that kind of brings us to the next part in this talk, which is to compare and contrast what agent development looks like versus what more traditional software engineering development looks like and why it demands a new set of tools to really understand what's going on and have confidence and trust. Um, so here's a here's a 2018 program right here. Uh, so you can tell already the purpose of the program is to extract phone numbers from text. And we have a rejax right here that uh looks for the phone number. And I can say with 100% confidence what will happen if I run this program 1 million times in a row. Um so now let's update it to the 2026 version. So uh I swap out my reax and instead obviously I throw in my model call instead and I say extract this phone number. Um, so in some ways this is actually a more powerful program because uh the reax was actually a little bit brittle. It would have missed any phone number that wasn't formatted exactly like how it was specified. Whereas I'm pretty confident that this program with GPT 5.5 will catch a lot of the phone numbers that are formatted weirdly. Um, however, if I ran this exact program one million times, I'm not 100% confident that it will print the same thing every single time or that I know exactly what it will print. Um, it probably gets it right almost every time. This is a pretty simple task. Um, but, uh, this is obviously far simpler than the things we're asking these models to do. And the uncertainty only increases as the complexity of the task increases. Uh so now let's come back to Francois's tweet and let's update it a little bit. We'll generalize it. So he says agentic coding and my claim is well just agents in general are a form of machine learning. And then he says generated code is best treated as a blackbox artifact and I say agent performance itself is best treated as a blackbox artifact.