Senior Data Annotator Jobs in Geneva

Senior Data Annotator (Remote, Full-Time)

Join Rex.zone to produce and validate high-quality labels used for model training and evaluation across NLP/LLMs and, as needed, computer vision. You will execute RLHF preference ranking, prompt evaluation, QA evaluation, and content safety labeling to improve training data quality and support model performance improvement.

What You Will Do

• Create gold-standard labels for complex tasks (classification, span labeling, NER, relation extraction, sentiment, safety)
• Execute RLHF workflows: pairwise ranking, preference labeling, rationale capture
• Perform prompt evaluation and response grading with calibrated rubrics (helpfulness, harmlessness, factuality)
• Run QA evaluation: audits, adjudication, inter-annotator agreement checks, error analysis, corrective feedback
• Document edge cases, update taxonomies, and propose guideline clarifications for consistent annotation guidelines compliance
• Support computer vision annotation (bounding boxes, polygons, keypoints) when required
• Partner with operations and engineering to improve tooling, sampling, and audit strategies
  
  

Required Qualifications

• Mid-Senior experience in data annotation/data labeling or AI evaluation with measurable quality outcomes
• Strong judgment, attention to detail, and ability to manage ambiguity while maintaining consistency at scale
• Hands-on experience with QA evaluation methods and quality gates
• Familiarity with LLM evaluation concepts, RLHF labeling patterns, and prompt evaluation workflows
• Strong written communication for documenting decisions and guideline updates
  
  

Preferred Qualifications

• Content safety labeling, moderation policy workflows, and safety taxonomy creation
• Background in structured NLP annotation (entities/relations) and NER
• Exposure to computer vision annotation tools
  
  

Compensation

$30–$50 per hour (base salary), depending on experience.