Andrej Karpathy

Karpathy's viral line predated vibe coding by two years. English became the interface — but agents, repos, and tests became the runtime. A 2026 read on prompt-as-program from GPT-3 to shipping software in plain language.

Meta FAIR released Brain2Qwerty v2 on June 25, 2026 — a three-module deep learning pipeline (CTC encoder, word aligner, fine-tuned LLM) that reads typed sentences directly from magnetoencephalography brain signals. 61% average word accuracy, 78% for the top participant. Claude Opus 4.6 agents were used to discover the best training configuration. Code is open source.

"AI agent" covers everything from a chatbot with one tool to a fleet of orchestrated coding agents. This guide maps every major type — reactive vs deliberative, ReAct vs plan-and-execute, coding vs research vs browser agents, single vs multi-agent — and tells you which to build when.

America outspends China 23-to-1 on private AI investment but barely leads on model benchmarks. US and Chinese AI startups are running different races — this guide maps funding, strategy, moats, and where each side actually wins.

Prompt engineering fixes your wording. Context engineering fixes what the model sees. This guide draws the precise line, shows concrete examples of each in action, and maps out when to reach for which tool.