I let AI write 100% of my code for 30 days. Here's what broke.

A software developer recently conducted a 30-day experiment, tasking an AI with writing 100% of their application code for a new SaaS product. While the AI excelled at scaffolding, boilerplate generation, and debugging specific snippets, the experiment revealed significant limitations. The author encountered nine major "breaks," primarily caused by architecture drift, the AI's inability to maintain global system coherence, and the generation of plausible but logically flawed code. The developer concluded that while AI is an excellent tool for typing and rapid prototyping, it lacks the senior-level judgment required for production-grade architecture and edge-case handling. The experiment highlights a growing concern: if AI replaces entry-level coding tasks, the industry must find new ways to train the next generation of senior engineers. Ultimately, the author suggests that AI should handle the typing, while humans must retain full control over the thinking and architectural decision-making.