Online STEM Engineer (Remote, United States)

Online STEM Jobs in the United States (Remote, Full-Time)Rex.zone is hiring a remote, US-based STEM Engineer to build and maintain engineering systems that support AI/ML workflows such as LLM training pipelines, data labeling QA, prompt evaluation, RLHF evaluation, and dataset quality measurement. You will collaborate across NLP, computer vision, and content safety labeling to improve training data quality and model performance.What You’ll Work OnDesign and maintain data workflows for NLP and computer vision annotation (e.g., NER, multimodal, content safety labeling)Build internal tools and dashboards for audit trails, sampling plans, and quality metrics (e.g., disagreement analysis)Standardize prompt evaluation rubrics and implement evaluator toolingEnable scalable RLHF data collection, evaluation, and feedback loopsResponsibilitiesOwn end-to-end delivery for systems supporting LLM training pipelinesBuild ETL/ELT jobs, data validation checks, dataset versioning, and automated testsImplement QA evaluation workflows (gold sets, consensus methods, review queues)Develop guideline compliance checks and content policy enforcement utilitiesIntegrate labeling throughput, quality, and cost signals with partners and vendorsRequired QualificationsMid-Senior experience in software engineering or data engineering with production systemsStrong Python and SQL; experience building reliable pipelines and testsFamiliarity with ML workflows, dataset curation, and evaluation conceptsAbility to define measurable quality metrics and operational toolingStrong written communication and ability to work asynchronously (remote)Preferred QualificationsExperience with data labeling programs, annotation platforms, or vendor integrationsExposure to LLM evaluation, prompt evaluation, and rubric-based scoringUnderstanding of RLHF concepts and sampling strategiesFamiliarity with computer vision annotation formats and quality controlsBackground in content safety labeling, policy enforcement, or trust & safetyHow To ApplyApply through Rex.zone with a resume highlighting production pipeline ownership and any experience with LLM training data, QA evaluation, RLHF evaluation, NLP, computer vision annotation, or content safety labeling.