Senior Data Annotator Jobs in Warsaw

Senior data annotator jobs in Warsaw on Rex.zone focus on producing high-quality training data for modern AI/ML systems. You will label and review text, image, audio, and video datasets, perform RLHF-style preference ranking, run prompt evaluation, and complete QA evaluation to improve large language model evaluation outcomes and overall model performance improvement. This remote, full-time role supports LLM training pipelines, NLP tasks like named entity recognition, computer vision annotation, and content safety labeling while ensuring annotation guidelines compliance, training data quality, and consistent reviewer calibration across projects.

Senior Data Annotator Jobs in Warsaw

About the Role

You will work on remote annotation workflows that create and validate training datasets for AI labs, tech startups, and annotation vendors. Your responsibilities include expert data labeling, RLHF preference annotation, rubric-based QA evaluation, and prompt evaluation for LLM behavior. You will apply detailed annotation guidelines compliance, document edge cases, and help drive training data quality improvements that impact model performance improvement and reliability.

What You Will Do

You will: (1) annotate and review datasets across NLP, computer vision annotation, and content safety labeling, (2) perform large language model evaluation tasks including pairwise ranking and multi-turn conversation grading aligned to RLHF, (3) execute QA evaluation by auditing samples, measuring inter-annotator agreement, and reporting defect patterns, (4) conduct named entity recognition and taxonomy tagging with consistent label definitions, (5) evaluate prompts and model outputs for helpfulness, harmlessness, factuality, policy compliance, and instruction following, (6) collaborate with project leads to refine guidelines, create examples, and reduce ambiguity, (7) provide structured feedback that improves labeling throughput and reduces rework.

Core Workflows and Domains

Projects may include: (1) LLM training pipelines with conversation annotation, tool-use evaluation, and preference data creation for RLHF, (2) NLP labeling such as named entity recognition, sentiment, intent, topic classification, and retrieval relevance judgment, (3) computer vision annotation including bounding boxes, polygons, keypoints, segmentation masks, and attribute tagging, (4) content safety labeling for policy categories, sensitive content, misinformation, and age-appropriateness, (5) QA evaluation and adjudication to standardize decisions and raise training data quality.

Requirements

You have: (1) demonstrated experience in data annotation or data labeling with measurable QA evaluation outcomes, (2) strong ability to follow annotation guidelines compliance while handling edge cases consistently, (3) experience with large language model evaluation, prompt evaluation, or RLHF-style ranking tasks, (4) excellent written communication for documenting decisions, disagreements, and escalation notes, (5) comfort working in remote, production-style environments with throughput, accuracy, and audit requirements.

Preferred Qualifications

Preferred: (1) experience with named entity recognition schemes and ontology/taxonomy management, (2) experience with computer vision annotation tools and mask/segmentation quality checks, (3) prior work on content safety labeling or policy enforcement evaluation, (4) familiarity with reviewer calibration, inter-annotator agreement, and adjudication processes, (5) exposure to AI labs, tech startups, BPOs, or annotation vendors delivering training data at scale.

Why Rex.zone

Rex.zone connects skilled annotators with real-world AI/ML training workflows, including RLHF, data labeling, and QA evaluation programs. You will work on impactful datasets used in LLM training pipelines and model evaluation cycles while building domain depth across NLP, computer vision annotation, and content safety labeling. This is a remote, full-time opportunity aligned to senior data annotator job intent for Warsaw-focused candidates.

How to Apply

Apply through Rex.zone with a concise summary of annotation experience, domains (NLP, computer vision annotation, content safety labeling), and examples of QA evaluation or guideline improvement work. Include availability for full-time remote work and highlight any experience with RLHF and large language model evaluation.

Frequently Asked Questions

Q: What are senior data annotator jobs in Warsaw on Rex.zone?
These are remote, full-time roles focused on creating and validating training data for AI/ML systems. The work includes data labeling, QA evaluation, prompt evaluation, and RLHF-style preference ranking to improve large language model evaluation and training data quality.
Q: Is this role remote even though it targets Warsaw?
Yes. The remote type is Remote, and you can work remotely while targeting Warsaw search intent and regional candidate interest.
Q: What types of tasks will I label or evaluate?
You may label text for NLP (including named entity recognition), annotate images for computer vision annotation, perform content safety labeling, and evaluate model outputs through QA evaluation, prompt evaluation, and RLHF preference tasks.
Q: What does RLHF-related annotation mean in practice?
It typically includes ranking responses, grading multi-turn conversations, evaluating helpfulness/harmlessness, and creating preference data that helps optimize model behavior in LLM training pipelines.
Q: How is quality measured for senior annotators?
Quality is measured via audit scores, adherence to annotation guidelines compliance, inter-annotator agreement, consistency on edge cases, and the ability to improve training data quality through clear documentation and feedback.
Q: Which employers use this type of training data work?
Common employer types include AI labs, tech startups, BPOs, and annotation vendors supporting model development and large language model evaluation programs.
Q: Is the role full-time or contract/freelance?
This posting is FULL_TIME. However, the broader field often includes contract and freelance annotation work depending on project needs.
Q: What skills should I highlight to match this job intent?
Highlight data annotation, data labeling, RLHF, QA evaluation, prompt evaluation, named entity recognition, computer vision annotation, content safety labeling, LLM evaluation, and strong annotation guidelines compliance.

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