The confusion may come from the various and evolving modalities of interacting with AI. There are many ways to work with AI, as explained in the 4D Framework for AI Fluency designed by Academics for their students and promoted by Anthropic.
What is seen as “Vibe coding” is usually the modality where the engineer delegates the coding work to AI, and uses the results without any understanding or judgement of what was actually produced. I wouldn’t recommend that for embedded systems, and any system in fact.
The second modality is the “coding assistant”, where the engineer uses the AI to generate code, test, document, but always stays in the loop, reviewing and vetting everything. While it may seem the “safe” way, this approach is the one that explains the 19% loss of productivity in the METR study. Indeed, the study highlights that the developers accepted less than 44 percent of the code generated by AI without modification, which demonstrates a heavy involvement of the human at every step.
Here is where it gets truly interesting. AI trailblazers have found ways to overcome this productivity barrier. For them, code generation is just the tip of the iceberg. They realized the transformative potential of AI with what they call compound engineering: integrating AI across the entire development lifecycle, not just the editor.
The financial analogy is apt: compound interest generates exponential returns because gains are continuously reinvested. Compound engineering works the same way: each completed task accelerates the next. The codebase self-documents, tests for one feature validate assumptions in the next, feedback loops close automatically, without a human in the critical path.
The productivity formula becomes code velocity multiplied by feedback quality multiplied by iteration frequency. Vibe coding improves only the first variable but degrades the two others. Coding assistant addresses the first two terms but slows the third one. Compound engineering compresses all three simultaneously. That is why the numbers diverge so sharply: 30 to 70 percent gains with coding assistant, versus 300 to 700 percent in early compound engineering implementations.
The key insight is that code generation is no longer the bottleneck. The whole code life cycle (test, validation, deployment) is. The teams achieving real gains are the ones who have invested in making the life cycle fast, automated, and comprehensive.