// Popular Articles
AVB drops a 50-minute GRPO + RLVR deep dive — and you watch logits move in real time
Avishek Biswas (@neural_avb) shipped a 50-minute long-form tutorial that walks through GRPO low-level mechanics, trains sub-1B SmolLM and Qwen3 models on text-based RLVR gym envs, and animates PPO updates so you literally see the policy logits shift. Code included.
Phantom Clipping: Why Your RLHF Run Stalls When Trainer Is FP32 and vLLM Is BF16
Hugging Face's TRL team finally pinpointed a long-suspected RLHF failure mode. It is not noise. It is PPO's clip silently zeroing out 18% of tokens because the trainer and the inference engine disagree at the bit level.