TL;DR: Karpathy says we’re in Software 3.0: big language models act like programmable building blocks where natural language is the new code. Don’t jump straight to fully autonomous “agents”—ship human-in-the-loop tools with an “autonomy slider,” tight generate-→verify loops, and clear GUIs. Cloud LLMs still win on cost, but on-device is coming. To future-proof, expose clean APIs and docs so these models (and coming agents) can safely read, write, and act inside your product.