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Rafael Tejon

Rafael Tejon

AI/ML Engineer with expertise in LLM workflows, agents, and automation

Colombia flagBogota, Colombia
$30.00/hrExpertAws SagemakerData Annotation TechGoogle Cloud Vertex AI

Key Skills

Software

AWS SageMakerAWS SageMaker
Data Annotation TechData Annotation Tech
Google Cloud Vertex AIGoogle Cloud Vertex AI
Redbrick AIRedbrick AI
Internal/Proprietary Tooling

Top Subject Matter

No subject matter listed

Top Data Types

Computer Code ProgrammingComputer Code Programming
ImageImage
TextText

Top Task Types

Classification
Computer Programming Coding
Data Collection
Fine Tuning
Function Calling

Freelancer Overview

I am an AI/ML engineer with solid experience designing, evaluating, and improving large-language-model systems, including multi-agent architectures, RAG pipelines, and high-quality prompt engineering. My work has involved constructing detailed evaluation datasets, crafting instruction-tuning samples, and curating domain-specific corpora used to improve model behavior, reliability, and alignment. I’ve built datasets for reasoning, persona consistency, safety, tool use, and multi-turn conversation, with an emphasis on clarity, annotation quality, and controlled diversity. I have contributed to real-time AI agents, including voice agents powered by LiveKit, where I refined prompts, structured evaluation suites, and generated synthetic and human-verified datasets to measure accuracy, latency, and user experience. I am comfortable working in highly iterative environments, analyzing model outputs, identifying failure modes, and producing high-quality training and evaluation data that directly improves system performance. My bilingual English–Spanish skills also allow me to create and evaluate multilingual datasets effectively.

ExpertEnglishSpanish

Labeling Experience

AWS SageMaker

Fine-tune LLM style

Aws SagemakerTextFine TuningData Collection
With content from letters, blog posts and video transcription, create dataset to fine-tune LLM to have the style of Andrew Ng

With content from letters, blog posts and video transcription, create dataset to fine-tune LLM to have the style of Andrew Ng

2025 - 2025

Jailbreak LLM evaluation dataset

Internal Proprietary ToolingTextClassificationEvaluation Rating
Crate a dataset to find queries that had jailbreak a voice agent. then creating a benchmark to evaluate next iterations of the agent

Crate a dataset to find queries that had jailbreak a voice agent. then creating a benchmark to evaluate next iterations of the agent

2025 - 2025
AWS SageMaker

Automatic Students Programming Project Evaluator

Aws SagemakerComputer Code ProgrammingComputer Programming CodingData Collection
I reviewed and evaluated Python programming assignments submitted by university students, checking code correctness, adherence to requirements, and overall logic. This included reading project specifications, analyzing each solution, labeling errors or missing functionality, and generating clear feedback. I also created prompt and response examples for automated evaluation experiments and collected structured metadata to support future model training. All work followed consistent quality guidelines and validation checks inside AWS SageMaker.

I reviewed and evaluated Python programming assignments submitted by university students, checking code correctness, adherence to requirements, and overall logic. This included reading project specifications, analyzing each solution, labeling errors or missing functionality, and generating clear feedback. I also created prompt and response examples for automated evaluation experiments and collected structured metadata to support future model training. All work followed consistent quality guidelines and validation checks inside AWS SageMaker.

2019 - 2019

Education

U

Universidad de los Andes

Master of Science, Information Engineering

Master of Science
2023 - 2025
U

Universidad de los Andes

Postgraduate Diploma, Mathematics

Postgraduate Diploma
2016 - 2021

Work History

R

RealAvatar.ai

AI/ML Engineer

N/A
2025 - 2025
S

Slang

Machine Learning Engineer

N/A
2022 - 2025