# Hugging Face Stops Pretending Post-Training Is Solved - Date: 2026-03-31 - Category: Artificial Intelligence 3 million times a month, engineers import TRL — the post-training library that just drew a versioned line between the methods it trusts and the ones it is still figuring out. This is Hugging Face’s answer to a field rewriting its own foundations three times in just over six years. ---