Senior Data Labeling Specialist

Senior Data Labeling Specialist (Remote, Full-Time) Rex.zone is seeking a Mid-Senior Data Labeling Specialist to lead complex annotation and evaluation work that improves training data quality and large language model evaluation outcomes. This posting targets candidates searching for senior data labeling jobs in Hamburg, but the role is explicitly Remote .

What You Will Do

• Execute and review data labeling across NLP, computer vision, and content safety domains
• Run QA evaluation, adjudicate disagreements, and improve inter-annotator agreement
• Perform RLHF preference ranking/labeling and write rationale aligned to rubrics
• Complete prompt evaluation for helpfulness, harmlessness, and instruction-following
• Validate training data quality using sampling plans, error taxonomies, and root-cause analysis
• Maintain annotation guidelines compliance and propose updates for edge cases
• Collaborate with engineering and data ops to improve tooling, throughput, and auditability
• Document decisions to support reproducible LLM training pipelines

Required Qualifications

• Mid-Senior experience in data labeling/data annotation/AI evaluation
• Strong grasp of annotation guidelines compliance and training data quality practices
• Hands-on exposure to RLHF workflows (preference ranking, rubric-based scoring)
• Familiarity with NLP concepts including named entity recognition and taxonomy design
• Familiarity with computer vision annotation formats and quality checks
• Experience with content safety labeling, policy interpretation, and escalation workflows
• Ability to communicate edge cases clearly and write consistent rationales
• Comfort working remotely with cross-functional teams and meeting full-time targets

Compensation Base pay range: $30–$50 per hour (USD).