In late 2025, Andrej Karpathy described going from roughly 80% manual coding to 80% agent coding in a matter of weeks, calling it the biggest change to his workflow in two decades of programming. Coding agents like Claude Code and Codex can now explore a codebase, plan a change, write it, run it, and test it with minimal supervision. Yet the people getting reliably good output are not the ones with the cleverest prompts. They are the ones who noticed that the bottleneck has moved: writing code is now cheap, and deciding whether to trust it is the expensive part. This post distils what top practitioners converge on into seven working principles, aimed at anyone using these tools to build real things.

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Table of Contents

Table of Contents

Table of Contents

Table of Contents