---
type: source
title: "Programming fundamentally changed in December 2025 — coding agents basically didn't work before and basically work since"
author: "Andrej Karpathy (@karpathy)"
twitter_id: "33836629"
url: https://x.com/karpathy/status/2026731645169185220
date: 2026-02-25
domain: ai-alignment
secondary_domains: [teleological-economics]
format: tweet
status: unprocessed
priority: medium
tags: [coding-agents, ai-capability, phase-transition, software-development, disruption]
---

## Content

It is hard to communicate how much programming has changed due to AI in the last 2 months: not gradually and over time in the "progress as usual" way, but specifically this last December. There are a number of asterisks but imo coding agents basically didn't work before December and basically work since - the models have significantly higher quality, long-term coherence and tenacity and they can power through large and long tasks, well past enough that it is extremely disruptive to the default programming workflow.

## Agent Notes

**Why this matters:** 37K likes — Karpathy's most viral tweet in this dataset. This is the "phase transition" observation from the most authoritative voice in AI dev tooling. December 2025 as the inflection point for coding agents.

**KB connections:** Supports [[as AI-automated software development becomes certain the bottleneck shifts from building capacity to knowing what to build]]. Relates to [[the gap between theoretical AI capability and observed deployment is massive across all occupations]] — but suggests the gap is closing fast for software specifically.

**Extraction hints:** Claim candidate: coding agent capability crossed a usability threshold in December 2025, representing a phase transition not gradual improvement. Evidence: Karpathy's direct experience running agents on nanochat.

**Context:** This tweet preceded the autoresearch project by ~10 days. The 37K likes suggest massive resonance across the developer community. The "asterisks" he mentions are important qualifiers that a good extraction should preserve.