Big non-tech companies are quietly fine-tuning open-weight models in-house

ivan_bezdomny · x · 2026-09-14

A pattern is emerging: the biggest non-tech companies fine-tune open-weight models on their sensitive data and proprietary evaluations instead of relying on closed APIs.

The playbook: a small internal post-training team designs the datasets and evaluations, hires contractors under NDA, then contracts the actual post-training to post-training startups — similar to what Harvey did. The author plans an article and video noting that finetuning isn't complicated but is fragile: default parameters often don't fit your problem, and it's non-obvious which metrics to watch or how much data you need.

Original post →

More from Venture

Venture channel →