The 90/10 Rule: The Inconvenient Truth About Agentic AI - It’s All Plumbing, No Brain

The Real Challenge in Building AI Agents Isn’t the AI - It’s Everything Else The AI industry has a marketing problem. We’ve become so infatuated with the “intelligence” in artificial intelligence that we’ve forgotten the most important truth about building agentic AI systems: 90% of the work is software engineering, and only 10% is actually about the AI model itself. This isn’t just a hot take - it’s a hard-learned lesson from intense 11 months of building AI interview and agentic systems at Eightfold AI, where this realisation became both the problem statement and a career pivot. While everyone’s debating which foundation model has the highest benchmark scores, the real battles are being fought in error handling, state management, and API integrations. ...

September 10, 2025 · 6 min · 1127 words · Thiyagaraj T