Machine Learning Test Engineer, Transformers team

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

We are seeking a highly motivated Senior Test Engineer to join our Transformers team, where you will play a pivotal role in advancing one of the most critical aspects of our mission: testing. As projects like Transformers, PyTorch, and vLLM rapidly expand in scale and complexity, the testing infrastructure must evolve in tandem. With over 100,000–150,000 tests for the Transformers library alone—and the need to support diverse platforms—this role is essential to ensuring our testing ecosystem scales seamlessly to meet growing demands.

This is not a conventional testing role. You will own the strategic redesign and scaling of our testing infrastructure, ensuring it keeps pace with the relentless growth of our projects. While every engineer contributes to testing for their features, we need someone with a bird's-eye view to champion testing as a core enabler of growth, rather than an afterthought.

Key Responsibilities:

• Lead the reinvention and scaling of testing infrastructure to support 100K+ tests across multiple platforms (e.g., Transformers, PyTorch, vLLM).
• Design growth-oriented testing architectures that prioritize scalability, reliability, and integration with CI/CD pipelines, avoiding fragmented or isolated test workflows.
• Partner with the existing testing lead to establish best practices and drive continuous improvement of the testing ecosystem.
• Collaborate with cross-functional teams to embed testing as a first-class project, ensuring it receives the focus and resources required to sustain rapid growth.
• Anticipate future testing needs and proactively adapt systems to accommodate evolving project scope, complexity, and platform diversity.

About you

• Proven experience working with modern machine learning frameworks (e.g., Transformers, PyTorch) and large-scale software projects.
• A mindset that treats testing as a strategic priority, not a secondary task—demonstrating how robust testing directly enables project scalability.
• Strong belief in architecting for growth: You prioritize scalable, modular testing systems over isolated, atomic tests.
• Experience managing high-volume test suites (100K+ tests) and cross-platform testing challenges.
• Familiarity with CI/CD tools and automated testing frameworks.

Preferred Qualifications:

• Background in open-source development or contributions to major ML libraries.
• Experience in re-architecting testing systems for rapidly growing projects.

If you're interested in joining us, but don't tick every box above, we still encourage you to apply We're building a diverse team whose skills, experiences, and background complement one another. We're happy to consider where you might be able to make the biggest impact.

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 offer health, dental, and vision benefits for employees and their dependents. We also offer parental leave and flexible paid time off.

We support our employees wherever they are. While we have office spaces in NYC and Paris, 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 want our teammates to be shareholders. All employees have company equity as part of their compensation package. If we succeed in becoming a category-defining platform in machine learning and artificial intelligence, everyone enjoys the upside.

We support the community. We believe major 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.