Mercor

Machine Learning Engineer, Frontier Data Products

San Francisco

Sponsorship not specifiedDetected 53 days ago

PythonPostgreSQLAWSTemporalMachine LearningLLMsMLOps

About the role

Frontier AI companies are increasingly bottlenecked on expert judgment - capturing it reliably, validating it at scale, and turning it into durable model behavior.
This role sits at the center of that problem.
A single job can stay live for days, interleaving model inference, automated checks, expert review, disagreement resolution, and feedback loops.

Build ML systems that score, validate, and improve complex work products where correctness is nuanced and labels are imperfect.
Design evaluation frameworks for ambiguous tasks where ground truth is partial, delayed, or disputed.
Build feedback loops that turn review, disagreement, correction, and adjudication into measurable model and system improvements.
Own production ML behavior end-to-end: precision/recall tradeoffs, regression detection, drift, latency, cost, and explainability.
Partner with backend engineers to integrate inference into durable, long-running workflows without sacrificing debuggability or human oversight.

Track record of shipping ML systems that improved a real product, workflow, or business metric.
Comfort operating in ambiguous problem spaces where labels are imperfect and correctness evolves.

Familiarity with LLM applications, model-assisted workflows, evaluation frameworks, or human-in-the-loop ML is a strong plus.

Bi-annual performance bonus structure.
Generous equity grant vested over 4 years.
Up to $15k Relocation bonus.
$10K housing bonus (if you live within 0.5 miles of our office).
$1.5K monthly stipend for meals.
$200 monthly laundry reimbursement.
$200 monthly personal wellness reimbursement.
Health, Dental, Vision insurance.
Improve model quality using the right tool for the job - prompting, fine-tuning, retrieval, active learning, heuristics, and error analysis.

by sharing knowledge, experience, and context that can't be captured in code alone.
Today, more than 30,000 experts in our network collectively earn over $3 million a day.
Mercor is creating a new category of work where expertise powers AI advancement.
Achieving this requires an ambitious, fast-paced and deeply committed team.
You'll work alongside researchers, operators, and AI companies at the forefront of shaping the systems that are redefining society.
Mercor is a profitable Series C company valued at $10 billion.
We work in-person five days a week in our San Francisco, NYC, or London offices.
The feedback loop is short: shipping a model behavior change directly and visibly affects what customers receive.

This listing is sourced directly from Mercor's careers page and normalized into a canonical job model.