
Pierre-Carl Langlais on Building Models from Data You Can Account For
Published: July 23, 2026
Duration: 1:05:39
Most labs build language models by scraping the web and filtering afterward. Pierre-Carl Langlais runs it the other way around. At Pleias, the French-German lab he co-founded, the models are built from data he can actually account for, which in practice means open and public-domain sources plus a lot of synthetic data the lab generates itself. It sounds like a self-imposed handicap. It mostly isn't. One of their models is a 600 million parameter system that runs live inside the Paris subway's monitoring pipeline.
We cover the SYNTH pretraining dataset and why he thinks "ethical data" has to...