Models Open Weight Jobs in San Francisco, CA

models to a specialized domain You've built training data or evaluation infrastructure You contribute to open source projects

Work directly with model internals to improve behavior and performance across commercial and open-source models.

Work on safety alignment of our models for open source release.

About the Role Together serves a broad portfolio of open-weight models, backed by infrastructure designed to run them quickly and efficiently

We're creating a powerful flywheel where more compute trains better models, better models power more useful products, and what we learn from people using those products

Founded by the creators and core maintainers of vLLM, we sit at the intersection of models and hardware, a position that took years to build.

Profile model architectures and workloads to understand bottlenecks across compute, memory, communication, and model execution.

- Train / fine-tune VLAs and robot foundation models - Run data-quality ablations and scaling studies - Publish papers and benchmarks - data

Work with ML infrastructure engineers to scale training and inference of your models and with product teams to align your model’s behavior with

• Research in model behavior, open-ended generation, or preference learning, with rigorous human evaluation and experimental design.

, and pre-training at massive scale for fully custom intelligence, all around a marketplace of leading open models that teams can run, adapt, and own.

Build on existing model families and open-source tooling first (vision foundation models, VLMs, point-cloud backbones, classical geometry), and

You’ll help turn open-ended questions about model behavior into well-defined ML problems, build methods that address them, and establish how reliably those methods

Experience with scaling studies for large models. Contributions to open-source training or inference frameworks.

The window to join early and own a meaningful piece of what comes next is open, but won't stay that way.