AI's 70% Problem — Zed's Blog

Addy Osmani from Google's Chrome team discusses the "70% problem" in AI coding: while AI tools can rapidly generate 70% of a solution, the remaining 30% involving edge cases, security, and production integration remains as challenging as ever. Despite over 30% of Google's code being AI-generated, trust in AI-generated code has declined from 70% to 60% in two years. The talk covers common pitfalls like the "two steps back" pattern where AI fixes create new problems, the reality that productivity gains are modest (1-2x) compared to hype, and code review becoming a new bottleneck. Osmani emphasizes that developers must understand and take responsibility for AI-generated code, especially junior developers who should use AI as a learning aid while maintaining curiosity.