In his keynote at the Software Architecture Gathering 2025, Vaughn Vernon – software ecologist, architect, modeler, and optimizer of teams and individuals – introduces the concept of "Stochastic Architecture." Drawing on hands-on experience with AI-assisted software development, he explains why Large Language Models are not reasoning systems but probabilistic prediction engines, and why software craftsmanship remains essential in the age of AI.

Key Takeaways:

1. LLMs generate statistically probable answers rather than reasoned conclusions
2. AI systems are designed to be convincing, not necessarily correct
3. Hallucinations are a natural consequence of how Large Language Models work
4. Speed is abundant, but software craftsmanship remains scarce
5. Tests generated by AI should be reviewed as critically as production code
6. Domain-Driven Design and bounded contexts help teams work effectively within AI limitations

Watch the full keynote to learn how software architects can leverage AI responsibly while maintaining quality, correctness, and architectural integrity.