Senior Data Labeling Jobs in Chicago

Overview Rex.zone is hiring senior data labeling professionals aligned with Chicago-based searches, but this role is fully Remote. You will produce high-quality labeled datasets and evaluation signals that improve AI/ML system performance across LLMs and computer vision. What You Will Do Lead complex NLP, LLM evaluation, and computer vision annotation projectsExecute RLHF preference labeling (pairwise preference, ranking, justifications) and prompt evaluationRun QA evaluation using gold sets, sampling plans, spot checks, and adjudicationPerform named entity recognition and structured extraction labeling with consistent schemasLabel content safety categories (hate, harassment, self-harm, sexual content, violence) using policy rubricsAnalyze disagreement patterns, create error taxonomies, and drive training data quality improvementsPartner with engineering/product on dataset specs, schema, and acceptance criteriaMaintain documentation, decision logs, and versioned guideline updates; mentor annotators Required Qualifications Mid-senior experience in data labeling/data annotation/AI evaluationStrong annotation guidelines compliance and calibrated decision-making under ambiguityHands-on QA practices (gold sets, inter-annotator agreement, adjudication)Familiarity with RLHF, preference labeling, and prompt evaluation for LLMsExcellent written communication for rationales and decision logs Pay $30–$50 per hour (base pay; rate depends on experience and project scope). How To Apply Apply via Rex.zone and include a short summary of your senior labeling experience, QA methods used, and any RLHF/prompt evaluation work.