Beating GPT-5.6 Sol on retrieval with 100x cheaper open models

Castform and Neon have developed a system combining RL post-training with advanced search infrastructure to enable smaller open-source models to outperform GPT-5.6 Sol in retrieval tasks at 100x lower cost. This approach uses Neon’s Lakebase Postgres and Search extensions with Castform’s training pipeline to improve multi-turn search efficiency and reduce latency and expense.