Remote STEM Engineer (Brazil)

**Remote STEM Jobs in Brazil** Rex.zone connects remote professionals with AI/ML and engineering work that strengthens model training pipelines, improves dataset reliability, and supports scalable evaluation operations across distributed teams. **What You Will Do** * Support AI/ML pipelines through data labeling tooling, QA evaluation, and training data quality checks * Execute prompt evaluation and structured feedback loops (RLHF) tied to large language model evaluation * Validate named entity recognition outputs and perform error analysis for NLP tasks * Review computer vision annotations (e.g., bounding boxes/segmentation) and ensure guideline compliance * Perform content safety labeling reviews using established taxonomies and rubrics * Create audit\-ready documentation, metrics reporting, and issue tracking to reduce rework cycles **Required Qualifications** * Mid\-Senior engineering experience in a STEM domain * Strong problem\-solving, documentation habits, and comfort working fully remote * Ability to follow detailed rubrics and evaluation instructions precisely * Working knowledge of Python and SQL for analysis and validation **Tools \& Workflow** * Python, SQL, spreadsheet\-based QA workflows, issue tracking, and internal annotation/evaluation tools * Dataset QA practices such as sampling strategies, consistency checks, and reproducible reporting **Compensation** Competitive hourly rate: **$30–$50/hr** (USD). Remote Type: Remote. Employment Type: Full\-time.