STEM Research Jobs in Brazil at Rex.zone Join a full-time, remote STEM research-focused engineering role improving AI/ML training pipelines through applied research, evaluation, and data operations. You will translate research questions into measurable studies, create datasets and evaluation protocols, and strengthen large language model evaluation tied to training data quality and model performance improvement. Key Responsibilities
Design and run experiments that measure model behavior and data quality impacts
Build and analyze datasets for named entity recognition, content safety labeling, and model evaluation
Create annotation guidelines and ensure annotation guidelines compliance across contributors
Execute RLHF evaluation and prompt evaluation workflows; document rubrics and edge cases
Perform QA evaluation on labeled data and evaluations to reduce noise and bias
Collaborate with engineering teams to integrate findings into training iterations
Maintain reproducible research practices: versioning, documentation, and audit-ready artifacts
Track metrics tied to evaluator agreement, training data quality, and performance improvement
Required Qualifications
Mid-Senior experience in STEM research, engineering R&D, or applied research
Strong experimental design, statistical reasoning, and data analysis skills
Proficiency with Python and common data/science tooling
Ability to write research documentation that is clear, testable, and reproducible
Familiarity with machine learning fundamentals and evaluation methods
Comfort working remotely with cross-functional stakeholders
Compensation
$30–$50 per hour (USD), based on skills and experience