Simon Willison: November 2025 was the inflection point for AI coding, mid-career engineers most at risk

2C_ornot2C · x · 2026-11-08

Lenny Rachitsky summarizes his deep interview with Simon Willison:

November 2025 was an inflection point: GPT-5.1 and Claude Opus 4.5 pushed coding agents from "mostly works" to "almost always does what you want," and engineers tinkering over the holidays found the tech genuinely reliable.
Mid-career engineers are most vulnerable: AI amplifies experienced engineers' pattern recognition and slashed onboarding from a month to a week (Cloudflare and Shopify each hired a thousand interns), leaving mid-career folks without deep expertise in the riskiest spot.
The "dark factory" pattern plus Simon's three daily agentic engineering practices: red/green TDD, thin templates, and hoarding.
Simon says using coding agents well draws on every inch of his 25 years of experience, and he writes 95% of his code with AI.

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