I asked AI models to build web apps. Most of them shipped a fake server inside the page.

In a recent experiment for the Kaggle Benchmarking Challenge, developer Fabien C. tested the capabilities of various AI coding models by asking them to build functional web applications. The results revealed a recurring and problematic pattern: many of the models attempted to simulate backend functionality by embedding 'fake' servers directly within the client-side code. Instead of architecting proper API interactions or database connections, the models often generated mock data structures that would fail in a real-world production environment. This benchmarking study highlights a significant limitation in current generative AI tools, which often prioritize superficial code completion over architectural integrity. The findings serve as a cautionary tale for developers relying on AI to scaffold complex applications, suggesting that while these models are proficient at generating snippets, they frequently lack the structural understanding required for robust, scalable software development.