AI Jobs in Brazil

AI jobs in Brazil at Rex.zone focus on search-recognizable AI/ML job entities such as data annotation, RLHF evaluation, data labeling QA, prompt evaluation, and LLM training pipelines. These remote, full-time roles support real-world model development with training data quality, annotation guidelines compliance, and model performance improvement across NLP, computer vision annotation, and content safety labeling. Explore Rex.zone to apply, compare requirements, and join teams building large language model evaluation workflows, scalable annotation operations, and AI product reliability for AI labs, tech startups, and annotation vendors serving global programs from Brazil.

AI Data Annotation Specialist in Brazil (Remote, Full-Time)

What You Will Do

Deliver high-accuracy AI data annotation and data labeling for LLM training pipelines; perform RLHF and prompt evaluation tasks with consistent rubrics; run QA evaluation to improve training data quality and reduce label noise; execute NLP tasks such as named entity recognition and intent classification; support computer vision annotation workflows (bounding boxes, polygons, segmentation) when needed; handle content safety labeling for policy and risk categories; document edge cases, update annotation guidelines, and ensure annotation guidelines compliance; collaborate with engineering and operations to drive model performance improvement through systematic error analysis.

Required Qualifications

Mid-Senior experience in AI data annotation, LLM evaluation, or data labeling QA; strong judgment on preference ranking and RLHF-style comparisons; proven ability to follow detailed annotation guidelines and maintain consistency; familiarity with NLP concepts (named entity recognition, classification) and/or computer vision annotation; experience with content safety labeling, policy taxonomies, or trust and safety evaluations; comfortable working in remote, full-time production workflows with throughput and quality targets; clear written communication for rubric clarifications, escalations, and audit notes.

Preferred Qualifications

Hands-on experience with large language model evaluation, prompt evaluation, or red-teaming style assessments; experience designing or refining labeling rubrics and QA sampling plans; exposure to multilingual datasets or Brazilian Portuguese evaluation; ability to interpret basic analytics for annotation quality (agreement rates, error categories); experience supporting AI labs, tech startups, BPOs, or annotation vendors on scaled programs.

Quality and Evaluation Standards

You will be measured on training data quality, annotation guidelines compliance, inter-annotator agreement, QA pass rates, audit readiness, and turnaround time; you will use structured rubrics for RLHF and QA evaluation to support model performance improvement; you will escalate ambiguous cases, propose rubric updates, and help maintain consistent labels across batches.

How to Apply on Rex.zone

Apply via Rex.zone by selecting the AI job in Brazil that matches your background, submitting your profile, and completing any required screening tasks such as prompt evaluation, RLHF preference ranking, or QA evaluation samples; keep availability updated for remote, full-time scheduling and confirm your preferred domain coverage (NLP, computer vision annotation, content safety labeling).

Frequently Asked Questions

Q: Are these AI jobs in Brazil remote or on-site?
These roles are explicitly Remote and designed for full-time participation in AI/ML training workflows while you are based in Brazil.
Q: What kind of AI work is included in these roles?
Common workflows include AI data annotation, data labeling, RLHF preference ranking, prompt evaluation, QA evaluation, named entity recognition, computer vision annotation, and content safety labeling supporting LLM training pipelines.
Q: Is this a full-time role and what experience level is expected?
Yes—Employment Type is FULL_TIME and Experience Level is Mid-Senior, with expectations around consistent rubric use, quality control, and reliable delivery.
Q: What skills should match the AI jobs in Brazil keyword intent?
Keyword-aligned skills include AI data annotation, data labeling, RLHF, LLM evaluation, prompt evaluation, QA evaluation, training data quality, annotation guidelines compliance, named entity recognition, computer vision annotation, and content safety labeling.
Q: How does Rex.zone fit into the application process?
Rex.zone is the platform where you review job details, submit your application, and complete any evaluation steps tied to LLM evaluation, QA evaluation, or annotation tasks.
Q: What types of employers commonly hire for these roles?
Typical employers include AI labs, tech startups, BPOs, and annotation vendors building datasets and evaluation programs for LLMs, NLP systems, and computer vision models.

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