Research Engineer, Tinker, Developer Experience

Thinking Machines Lab•San Francisco, CA

20h•$350,000 - $475,000•Onsite

About The Position

Thinking Machines Lab's mission is to empower humanity through advancing collaborative general intelligence. We're building a future where everyone has access to the knowledge and tools to make AI work for their unique needs and goals. We are scientists, engineers, and builders who’ve created some of the most widely used AI products, including ChatGPT and Character.ai, open-weights models like Mistral, as well as popular open source projects like PyTorch, OpenAI Gym, Fairseq, and Segment Anything. Research Engineer, Tinker, Developer Experience About Tinker Thinking Machines empowers researchers and developers to customize frontier AI to their needs — opening access to capabilities that have previously been concentrated in a handful of labs. Tinker is our fine-tuning API, allowing users to train open-weight models flexibly while we manage the distributed training infrastructure. Tinker’s customers include independent hackers, research institutions, and major enterprises. We are rapidly expanding both Tinker’s user base and its features. About the Role We’re hiring a research engineer focused on developer experience to build Tinker while using Tinker — working hands-on with real users and turning their challenges into product improvements. You’ll write and update cookbook recipes, add library features, prototype integrations, and ensure users can customize models smoothly. This role is a bridge between Tinker users and our research and infrastructure teams. You’ll surface user patterns to guide product and infrastructure priorities, and share what you learn through blog posts, demos, and code examples. This is a technical-first role with a major user-facing component. It’s ideal for someone who’s happiest in a code editor or Jupyter notebook, but who also enjoys talking to creative people. Tinker is flexible by design to empower novel and ambitious use cases for model fine-tuning — your job is to help them succeed.

Nice To Haves

Experienced with fine-tuning large language models (LLMs) with supervised and reinforcement learning, and how to tune the hyperparameters of these algorithms.
Experienced with developing software libraries, especially open-source libraries.
Are thoughtful about developer experience, with clear ideas around developer ergonomics, onboarding flow, and sharp edges.
Are passionate about engaging with open-source communities, whether by contributing code, answering questions, or sharing learnings.
Have written public or internal code examples, tutorials, or papers that helped others understand and apply technical concepts.
Are comfortable reasoning about model training, fine-tuning, and inference, and can credibly discuss tradeoffs between different approaches.

Responsibilities

Write, test, and maintain high-quality code examples, recipes, and documentation in the Tinker cookbook .
Work directly with a variety of users to debug technical issues and optimize their fine-tuning pipelines.
Partner with internal research and infra teams to identify and prioritize improvements to Tinker’s developer experience.
Build tools, integrations, and demos that reduce user friction and make it easy to experiment and deploy models.
Share insights from the field through posts, guides, and talks.
Help develop Tinker’s near-term roadmap and long-term product strategy.