STEM Careers

STEM Careers in the United States (Remote, Full-Time)

Rex.zone is hiring a US‑based, STEM‑aligned engineering professional to help build and evaluate real AI/ML systems with a focus on large language model (LLM) workflows. You will translate product goals into measurable evaluation signals, training data quality controls, and reliable tooling that improves model performance across iterations.

• Build and improve tooling for LLM evaluation, including prompt evaluation and QA evaluation loops
• Support RLHF evaluation feedback cycles and rubric‑based scoring
• Define and maintain annotation guidelines and automated compliance checks
• Design sampling strategies, acceptance criteria, and drift checks for training data quality
• Analyze error patterns and propose fixes that drive model performance improvement
• Partner with labeling teams/vendors on ambiguity resolution, rework reduction, and throughput/quality reporting
• Implement dashboards and metrics (e.g., inter‑annotator agreement, precision/recall proxies)
• Help enforce privacy, security, and policy constraints for sensitive datasets

• Mid‑senior experience in engineering, computer science, data science, or a related STEM field
• Strong programming fundamentals and ability to ship production‑quality tools
• Familiarity with ML concepts and LLM evaluation methods
• Experience with data labeling, QA evaluation, or dataset curation for NLP and/or computer vision
• Ability to write clear specs, rubrics, and annotation guidelines
• Strong analytical skills for debugging dataset and evaluation issues in a remote, cross‑functional environment

• Experience with RLHF or preference modeling workflows
• Hands‑on prompt evaluation and rubric‑based scoring
• Named entity recognition (NER), taxonomy/ontology design, or content safety labeling
• Vendor/BPO collaboration for large‑scale annotation operations

Hourly base salary range: $30–$50 per hour (USD).

Remote, full‑time role based in the United States.