Luis Lastras
IBM Research director of language and multimodal models; co-author of the Granite Switch 4.1 launch post
- Director of language and multimodal models, IBM Research1
Luis Lastras is IBM Research's director of language and multimodal models. Lastras is a co-author of the Granite Switch 4.1 launch post and of the Activated LoRA paper on adapters that can be switched in at inference time without reprocessing a conversation, an approach Granite Switch uses to combine a base Granite model with adapter functions.145
Generative computing at IBM Research
In April 2025 IBM Research described Lastras, then its director of language technologies, in connection with its work on activated LoRA (aLoRA) adapters, which Lastras co-authored. By June 2026 IBM Research described Lastras as its director of language and multimodal models, in a post introducing Granite Libraries and Project Granite Switch as part of IBM's approach to building LLMs with the modularity of software.251
Granite Switch adds a switching layer to a base Granite model so that adapter functions for tasks such as relevance scoring, query rewriting, hallucination detection and safety decisions can be activated at inference time. Lastras co-wrote the October 2026 post launching Granite Switch 4.1, which adds a decision adapter and speech recognition to the models.14
Information theory
Lastras is a co-author of a paper in the Proceedings of the National Academy of Sciences that extends Shannon's sender-receiver model of communication by giving the receiver a reasoning capability. IBM Research describes the work as a long-running research effort that Lastras pursued with a small team before it grew into a larger collaboration.3
Work
Granite Switch 4.1 8BOpen weights
Co-author, with Kate Soule, Subhajit Chaudhury and Hendrik Strobelt, of the October 2026 Hugging Face post launching the Granite Switch 4.1 models.4
Activated LoRA: Fine-tuned LLMs for Intrinsics (external site: arxiv.org)Published research
Co-author of the 2025 paper introducing activated LoRA adapters, which IBM describes as giving LLMs specialized capabilities at inference time without the delay of reprocessing the conversation.52
Career timeline
Apr 2025
Co-authored the Activated LoRA paper on inference-friendly adapters for LLMs.52
Jun 4, 2026
IBM Research introduced Granite Libraries and Project Granite Switch, quoting Lastras as director.1
Aug 28, 2026
IBM Research reported a PNAS paper, co-authored by Lastras, extending information theory to account for reasoning.3
Oct 15, 2026
Co-authored the Hugging Face post launching Granite Switch 4.1.4
Related people
More sourced profiles at the same organization, in the same field, or from the same school.
- Aaron TeoAlso at IBM
- Clément FarabetLanguage models
- Arvind KrishnaAlso at IBM
- David TalbyLanguage models
- Carlos CostaAlso at IBM
- Dong YuML frameworks and libraries
- David D. CoxAlso at IBM Research
- Fabian PedregosaML frameworks and libraries
- Francesca RossiAlso at IBM Research
- Gabriel SynnaeveLanguage models
- Hendrik StrobeltAlso at IBM Research
- Jeff DeanML frameworks and libraries
Is this you?
Profiles cover public professional work only, and every line cites a source. If something is out of date, missing or wrong, send a correction with a link to an official page and we will update it. Suggest a correction
Add this badge to your website or GitHub profile README. It links back to this page. It is not an endorsement or a rating.
Markdown (for a README)
[](https://unitedstatesofamericasuperintelligence.com/people/luis-lastras/)
HTML
<a href="https://unitedstatesofamericasuperintelligence.com/people/luis-lastras/"><img src="https://unitedstatesofamericasuperintelligence.com/badges/profile.svg" alt="Luis Lastras — Profile on USASI" height="20"></a>
This profile covers public professional work only, from the sources below. It is not an endorsement or a ranking. To correct or remove it, use the correction form.