Karpathy Says December 2025 Was the Moment Everything Flipped

Andrej Karpathy published what amounts to a manifesto for the next era of software. In a blog post summarizing his Sequoia Ascent 2026 fireside, he lays out three eras: Software 1.0 (humans write code), Software 2.0 (neural networks learn patterns from data), and Software 3.0 (LLMs programmed through prompts, context, tools, and memory).

The specific claim that got me: December 2025 was when his personal ratio inverted from writing 80% of code to delegating 80% to agents. I've felt this shift in my own work over the past six months using Claude Code in my personal projects. Not gradually. More like a step function. One month I was writing most of my code. The next month I was reviewing most of my code.

But the most useful part isn't the timeline. It's his verifiability heuristic: "Traditional software automates what you can specify; LLMs automate what you can verify." That's a decision framework you can use today. If you can look at the output and know whether it's right, an LLM can probably produce it. If you can't verify it without deep domain expertise, you still need a human in the loop.

This maps directly to what I see building solo. Layout components, API integrations, test scaffolding, data transformations. I can verify all of that by looking at it. Architectural decisions, user experience flows, the choice of what to build next. That's still me. The bottleneck moved from fingers to taste. And here's the thing nobody's saying out loud: taste is a design skill, not an engineering skill. My 20 years in visual communications are suddenly more relevant to my engineering career than my 15 years of writing code.

The timing matters. This drops in the same week that claude-code-best-practice hit 53.4K stars and Zerostack shipped a 1.0 Rust-native coding agent. Three independent signals pointing at the same shift. Karpathy names it. The community writes the playbook. And new tools make the infrastructure cheaper.

If you haven't internalized "automate what you can verify," start there. It's more useful than any framework recommendation I could give you.