Founding Machine Learning Engineer

About the Role

This is a founding-level, hands-on ML engineering role at a fast-growing Series A AI startup in the Bay Area, specializing in high-quality training data, post-training data pipelines, and model evaluation for frontier AI labs and enterprises. You'll work closely with leadership to design, train, and ship production-grade ML systems — while helping shape the technical culture and infrastructure from the ground up.

This role is fully on-site in Mountain View, CA. Candidates must be authorized to work in the US without visa sponsorship.

What You'll Do

• Build and optimize end-to-end ML pipelines, from data ingestion through to production deployment.

• Implement and fine-tune LLMs, embeddings, and generative models for real-world applications.

• Develop efficient training and inference systems leveraging distributed compute at scale.

• 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 across the organization.

What We're Looking For

Required

• 3–10 years of hands-on experience as an ML Engineer, Applied Scientist, or Research Engineer.

• Proficiency in Python and at least one of PyTorch, TensorFlow, or JAX .

• Proven experience building production-grade, end-to-end ML pipelines (data ingestion, training, deployment).

• Experience implementing and fine-tuning LLMs, embeddings, and generative models for real-world use cases.

• Hands-on experience with distributed training/inference and scalable ML systems.

• Familiarity with cloud platforms ( AWS, GCP, or Azure ) and ML tooling such as MLflow or Weights & Biases .

• Strong collaboration skills with cross-functional data and product teams.

• Bias for action, ability to work autonomously, and eagerness to build from scratch.

Nice to Have

• Experience with RL environments or evaluation frameworks for AI models.

• Background in agentic systems, tool-use pipelines, or multi-step execution trajectories.

• Prior experience at an early-stage startup or in a founding-engineer capacity.

Compensation & Benefits

• Salary: $220,000 – $300,000 per year, depending on experience.

• Equity participation as a founding team member.

• Opportunity to directly shape technical direction, culture, and hiring at an early-stage, high-growth company.

Location

• On-site in Mountain View, California.

• No visa sponsorship available — candidates must have existing US work authorization.