Writing about tokenizers

• Jul 13, 2026

  Speaking Thai, Part 2: Four Frozen Embeddings

  6 min read

  A LoRA debugging story about four embeddings that never got to learn anything. If you add tokens and freeze the base model, their embedding and LM-head rows still need to train.

  #post-training , #sft , #lora , #tokenizers , #ai-assisted

• Jul 9, 2026

  Why Is My Model Suddenly Speaking Thai?

  8 min read

  A debugging story about special tokens, GRPO, and the skip_special_tokens flags scattered across your RL stack. When your SFT'd model nails the format in eval, then falls apart the moment it enters the GRPO rollout.

  #rl , #post-training , #grpo , #tokenizers , #ai-assisted