The article discusses how Castform, a platform, enables developers to post-train open-source models to be cheaper, faster, and better than frontier models like GPT-5.6 Sol. It achieves this by using data in Postgres databases to train a 4B open-source model, making it as accurate as GPT-5.6 Sol. The platform utilizes Lakebase Search and Neon to provide the necessary infrastructure for post-training. This approach allows for significant cost savings and improved performance.