At Hugging Face, we’re on a journey to democratize good AI. We are building the fastest growing platform for AI builders with over 5 million users & 100k organizations who collectively shared over 1M models, 300k datasets & 300k apps. Our open-source libraries have more than 400k+ stars on Github.

About the Role

In the past year the focus of building LLMs has gradually shifted from pretraining to post-training. This means spending more and more time on figuring out how to get models follow instructions reliably, use tools and generally align with certain values. With over 10k Github stars and close to 1M monthly installs the TRL library has become one of the go-to libraries for post-training. It scales flexibly from a single GPU to large clusters of GPUs using PEFT and ZeRO and offers a wide range of trainers for the latest post training techniques such as PPO or DPO and many more. In addition it includes a user friendly CLI that allows training models with a single command.

During this internship, you will collaborate with the research team to integrate cutting-edge methods into the library, maintain a clean and scalable codebase, and ensure its usability through thoughtful documentation. You’ll actively engage with the TRL community by responding to issues, gathering feedback, and fostering collaboration through thoughtful discussions and support, ensuring the library continues to meet developers’ needs. Your contributions will directly influence thousands of developers globally, advancing the adoption of state-of-the-art post-training techniques and laying the groundwork for the next generation of customizable, instruction-following LLMs.

About You

We are looking for someone with knowledge and experience in some of the following areas:

1. Machine Learning: Fine-tuning large language models (LLMs) or vision-language models (VLMs), and optimisation techniques.
2. Software Development: Proficiency in Python, PyTorch, and frameworks like Hugging Face Transformers, with experience in distributed training and GPU acceleration.
3. Open-Source: Familiarity with Git/GitHub workflows, community engagement, documentation, and collaborative development.
4. Research and Experimentation: Exposure to cutting-edge ML research, benchmarking, and testing fine-tuning methods.
5. Tooling and Maintenance: Building tools to streamline workflows, ensuring software stability, backward compatibility, versioning, and delivering reliable releases.
6. Communication and Outreach: Writing blog posts, tutorials, and sharing updates on platforms like LinkedIn to engage with the community and make complex concepts accessible to a wider audience.

You’re passionate about open-source innovation and making advanced ML tools accessible globally. You value continuity in software development, ensuring users have a dependable and evolving library to rely on.

Even if you don’t check every box, we encourage you to apply—we value diverse skills, perspectives, and experiences that complement our mission.

More about Hugging Face

We are actively working to build a culture that values diversity, equity, and inclusivity. We are intentionally building a workplace where people feel respected and supported—regardless of who you are or where you come from. We believe this is foundational to building a great company and community. Hugging Face is an equal opportunity employer and we do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.

We value development. You will work with some of the smartest people in our industry. We are an organization that has a bias for impact and is always challenging ourselves to continuously grow. We provide all employees with reimbursement for relevant conferences, training, and education.

We care about your well-being. We offer flexible working hours and remote options. We support our employees wherever they are. While we have office spaces around the world, especially in the US, Canada, and Europe, we’re very distributed and all remote employees have the opportunity to visit our offices. If needed, we’ll also outfit your workstation to ensure you succeed.

We support the community. We believe significant scientific advancements are the result of collaboration across the field. Join a community supporting the ML/AI community.

Please provide a cover letter mentioning why you would like to work in open-source at Hugging Face. We encourage you to mention your skills, potential expertise, and topics on which you would like to work.