Post-Training

The answer is not the conversation Customer support is a useful place to begin, because the failure is easy to recognize. A customer asks a question. The AI gives a technically correct answer. Then the customer asks a follow-up that exposes confusion, irritation, a missing constraint, or a completely different intention. The system that looked excellent on the first turn suddenly looks like it has never met a human being. Which, to be fair, it has not. ...

The GPU bill is not the strategy The easiest way to make reinforcement learning for reasoning models sound impressive is to say: sample more responses, train longer, scale harder. It is also the easiest way to make the finance team develop a facial twitch. Modern reasoning-focused LLMs increasingly rely on reinforcement learning with verifiable rewards: generate multiple candidate answers, score them with a rule-based signal, and update the model toward better reasoning behavior. In mathematics and coding tasks, this has become one of the most important post-training recipes. But it has a small accounting problem, in the same way a leaking ship has a small moisture problem. ...

Failure is usually where an LLM training pipeline becomes wasteful. A model generates a weak answer. A judge gives it a low score. The trainer nudges the policy away from that behavior and asks the model to try again. Repeat the ritual with more samples, more rollouts, more compute, and more optimism than the situation strictly deserves. ...