For employers

Hire this AI Trainer

Sign in or create an account to invite AI Trainers to your job.

Invite to Job
Youngjoo Choi

Youngjoo Choi

AI data annotation and evaluation specialist

South Korea flagSeoul, South Korea
$13.00/hrIntermediateAppenOther

Key Skills

Software

AppenAppen
Other

Top Subject Matter

No subject matter listed

Top Data Types

AudioAudio
TextText
VideoVideo

Top Task Types

Audio Recording
Evaluation Rating
Translation Localization

Freelancer Overview

I’m an experienced AI Data Labeling and Quality Reviewer with 2+ years of hands-on experience in data annotation, linguistic evaluation, and AI training tasks. I’ve contributed to multiple global NLP and multimodal projects, specializing in English–Korean translation, search relevance evaluation, and audio data collection. My background in linguistics and information science, combined with strong attention to detail, allows me to produce consistently accurate and high-quality data for machine learning and LLM fine-tuning.

IntermediateEnglishJapaneseChinese Mandarin

Labeling Experience

Search Result Evacuation

OtherText
Performed multilingual search quality and web relevance evaluations, rating query-document alignment and intent satisfaction.

Performed multilingual search quality and web relevance evaluations, rating query-document alignment and intent satisfaction.

2025 - 2025

Meta Ad Evaculation

OtherTextRouting
Conducted advertisement and search result relevance evaluations for Meta (Facebook) Ads, focusing on semantic alignment, user intent matching, and cross-language contextual accuracy.

Conducted advertisement and search result relevance evaluations for Meta (Facebook) Ads, focusing on semantic alignment, user intent matching, and cross-language contextual accuracy.

2025 - 2025
Appen

Byran video translation

AppenVideoTranslation Localization
Participated in large-scale video translation and evaluation projects (EN↔KO), including transcription, translation accuracy assessment, and quality alignment with linguistic guidelines. Also contributed to audio recording and text-to-speech prompt datasets for speech recognition and synthesis training.

Participated in large-scale video translation and evaluation projects (EN↔KO), including transcription, translation accuracy assessment, and quality alignment with linguistic guidelines. Also contributed to audio recording and text-to-speech prompt datasets for speech recognition and synthesis training.

2025 - 2025

LLM fine-tuning

OtherTextQuestion AnsweringText Generation
Reviewed and validated AI-generated text data, ensuring naturalness, accuracy, and contextual appropriateness for Korean-language LLM fine-tuning.

Reviewed and validated AI-generated text data, ensuring naturalness, accuracy, and contextual appropriateness for Korean-language LLM fine-tuning.

2023 - 2024

Education

G

Goldcoast English Language Centre (Australia) • ESL Communication Skills

Course Completed , ESL

Course Completed
2023 - 2023
A

AICOL Gold Coast English School

Study, AICOL

Study
2023 - 2023

Work History

A

Appen

AI data

Sydney
2024 - 2025
F

Flitto

LLM

Seoul
2023 - 2023