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Cesar Liu De Castro

Cesar Liu De Castro

AI Data Trainer and Quality Analyst - Technology & Internet

Portugal flagLisboa, Portugal
$25.00/hrIntermediateOther

Key Skills

Software

Other

Top Subject Matter

No subject matter listed

Top Data Types

TextText

Top Task Types

Question Answering
Fine Tuning

Freelancer Overview

I am an experienced AI data trainer and quality analyst with a strong background in evaluating and annotating AI-generated text and voice outputs in English, Cantonese, and Mandarin. My expertise includes assessing linguistic accuracy, tone, naturalness, and dialect authenticity, as well as developing detailed quality guidelines and providing actionable feedback to optimize AI model performance. I have led teams to improve linguistic consistency, contributed to specialized domains such as mathematical and STEM content, and collaborated across functions to identify and resolve model issues. My hands-on experience spans rigorous data labeling, prompt creation, and quality assurance, ensuring the reliability and authenticity of AI systems across multiple languages and modalities.

IntermediateEnglishChinese Mandarin

Labeling Experience

Chinese AI Quality Analyst

OtherTextQuestion AnsweringFine Tuning
• Linguistic Guidelines & Quality Optimization: Developed Chinese-specific quality guidelines, driving a 20% quality score improvement (from 70% to 90%) within one week. • Team Leadership & Linguistic Alignment: Led a 15-member trainer team to refine AI models, resolving Chinese linguistic discrepancies and ensuring consistency. This leadership experience supports mentoring AI systems and coordinating cross-functional voice project efforts. • Team Coordination & Quality Assurance: Hosted weekly sync meetings to address team challenges, reviewed trainers’ work for adherence to guidelines and standards—strengthening expertise in feedback delivery and quality control for AI-related linguistic tasks.

• Linguistic Guidelines & Quality Optimization: Developed Chinese-specific quality guidelines, driving a 20% quality score improvement (from 70% to 90%) within one week. • Team Leadership & Linguistic Alignment: Led a 15-member trainer team to refine AI models, resolving Chinese linguistic discrepancies and ensuring consistency. This leadership experience supports mentoring AI systems and coordinating cross-functional voice project efforts. • Team Coordination & Quality Assurance: Hosted weekly sync meetings to address team challenges, reviewed trainers’ work for adherence to guidelines and standards—strengthening expertise in feedback delivery and quality control for AI-related linguistic tasks.

2024 - 2024

Education

T

The Chinese University of Hong Kong

Bachelor of Business Administration, Business Administration

Bachelor of Business Administration
2016 - 2019

Work History

I

Invisible Technologies

Expert Data AI Trainer

/
2024 - Present
B

Banco Comercial de Macau

VIP Relationship Manager

Macau
2021 - 2023