Duncan Kariuki

Key Skills

Software

CVAT

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Top Data Types

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Video

Top Label Types

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Freelancer Overview

I am an experienced AI training specialist with over four years of hands-on work in data annotation, model evaluation, and prompt engineering for machine learning projects. My expertise spans labeling and quality assurance for text, image, and audio data, with a strong focus on NLP tasks such as sentiment analysis, intent classification, and entity recognition. I have contributed to training and evaluating Large Language Models and conversational AI systems, using tools like Labelbox, Scale AI, Appen, Remotasks, and Amazon SageMaker Ground Truth. I am skilled in following complex annotation guidelines, identifying model weaknesses, and delivering structured feedback to improve AI accuracy and alignment. My technical background in computer science, combined with my attention to detail and adaptability to new tools, allows me to consistently deliver high-quality training data for AI development.

Labeling Experience

Data annotation

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Labeled and annotated thousands of text samples for NLP tasks including sentiment analysis, intent classification, entity recognition, and summarization. Conducted RLHF tasks, providing structured human feedback to improve AI model alignment and response quality. Identified model failure cases, hallucinations, bias, and ambiguity, and provided detailed feedback for model refinement.

Labeled and annotated thousands of text samples for NLP tasks including sentiment analysis, intent classification, entity recognition, and summarization. Conducted RLHF tasks, providing structured human feedback to improve AI model alignment and response quality. Identified model failure cases, hallucinations, bias, and ambiguity, and provided detailed feedback for model refinement.

2021 - 2025

Education

Work History