Founding ML Engineer

### About the Role This is a founding-level Machine Learning Engineer role at a well-funded Series A AI data and services startup based in Mountain View, CA. You will join a small, high-caliber team building and scaling core ML systems from the ground up — bridging research and engineering to design, train, and ship production-grade models for top AI frontier labs. This is a high-ownership position where your work directly shapes the company's technical culture, infrastructure, and long-term ML impact. The company specializes in high-quality training and post-training data, reinforcement learning environments, and intelligent agents — serving both frontier AI labs and enterprise customers. Visa sponsorship is **not available** for this role. ### What You'll Do * Build and optimize end-to-end ML pipelines, from data ingestion through to deployment. * Implement and fine-tune LLMs, embeddings, and generative models for real-world applications. * Develop efficient training and inference systems leveraging distributed compute. * Partner with data and product teams to translate ideas into measurable ML impact. * Contribute to model monitoring, evaluation, and continual learning frameworks. * Establish best practices in model versioning, reproducibility, and scalability. ### What We're Looking For **Required:** * 3–10 years of experience as an ML Engineer, Applied Scientist, or Research Engineer. * Proficiency in Python and at least one major ML framework: PyTorch, TensorFlow, or JAX. * Strong grasp of ML fundamentals — data preprocessing, feature engineering, model training, and optimization. * Hands-on experience with distributed systems and cloud ML infrastructure (AWS, GCP, or Azure). * Familiarity with MLOps tooling such as Weights & Biases or MLflow. * Comfort working with large datasets and high-throughput systems. * Strong bias for action, ability to work autonomously, and genuine excitement about building from scratch. ### Compensation & Benefits * **Base salary:** $220,000 – $300,000 USD annually * Equity participation as a founding team member * Opportunity to establish technical direction and culture at an early-stage, high-growth company ### Location * **On-site** — Mountain View, California, United States * Visa sponsorship is not available for this position Find [Jobs in United Kingdom](https://www.arbeitnow.co.uk) on Arbeitnow