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Xavier Caracter

AI ENGINEER | FULL-STACK LLM APPLICATIONS | PROMPT OPTIMIZATION | IT CONSULTANT

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About Me


Hello, my name is Xavier Caracter and I am a computer science M.S. student with hands-on experience building production-ready LLM systems and systematically optimizing prompts. I also have 4+ years of professional software engineering experience in API integration, systematic testing, and cross-functional collaboration with a proven track record designing, deploying, and iteratively improving AI applications through rigorous experimentation and evaluation. I am a quick learner and I am always looking for new challenges and opportunities to grow.


Email

xaviercaracter@gmail.com


Phone

(650) 518-3813


Address

723 Camino Plaza #105

San Bruno, CA, 94066

Experience

Production LLM System for Customer Support

Independent Research Project

  • Developed end-to-end conversational AI support agent using OpenAI GPT-4o mini, achieving 85% intent recognition accuracy across 200+ test queries.
  • Designed and evaluated 50+ prompt variations (temperature, role definitions, instruction clarity, and chain-of-thought techniques) to enhance response consistency and quality.
  • Implemented prompt chaining for multi-step processes (verification, diagnosis, resolution), boosting task completion accuracy by 35%.
  • Built reusable prompt template library with 15+ patterns for key scenarios such as order tracking, returns, and billing inquiries.
  • Architected microservices infrastructure with REST API integration to inject real-time customer data into responses.
  • Deployed RAG pipeline grounded in knowledge base, reducing hallucination rate from 30% to under 5%.
  • Created LLM-as-judge evaluation system to assess helpfulness, accuracy, and tone; ran A/B tests on 300+ conversations to quantify improvements in customer satisfaction.
  • Conducted adversarial testing and implemented guardrails to mitigate prompt injection and jailbreak attacks.
  • Analyzed 500+ conversation logs to identify common customer intents, optimize prompt templates, and improve agent performance.

Buff Bros — Rancho Cordova, CA

Web Development Contractor

  • Built responsive business website with API-integrated contact form generating 40+ customer inquiries in first month.
  • Worked directly with client to understand business needs and translate requirements into technical solutions.

Boise State University

Senior Capstone Project

  • Developed a comprehensive tutoring web application for the Boise State University College of Education’s Literacy Lab.
  • Engineered numerous front-end components leveraging the Angular framework and integrating them with the backend built on Golang and GIN.
  • Designed and developed SQL queries and API endpoints that enabled secure and efficient data retrieval and management- this ensured optimized web application performance and functionality.

Micron Technology — Boise, ID

Revenue Operations Intern

  • Automated sales data pipeline and validation scripts (50k+ records), reducing reporting errors by 36% and eliminating 12 hours/week of manual effort.
  • Applied systematic experimentation methodology to test 12+ data validation approaches, measuring precision/recall metrics to optimize anomaly detection accuracy.
  • Created adopted documentation and presented solutions to cross-functional sales operations team.
  • Worked cross-functionally with sales operations team to understand ambiguous requirements and deliver impactful solutions.

Enterprise Transformation Institute — San Francisco, CA

Junior Software Engineer

  • Developed and maintained 25+ Selenium automation scripts across 8 client projects.
  • Integrated test automation into CI/CD pipelines, reducing regression testing time by 36%.
  • Designed systematic testing frameworks with defined success metrics (methodology later applied to LLM prompt optimization).
  • Debugged production issues using JavaScript, Python, and SQL in ambiguous, fast-paced environments.

Education

Johns Hopkins University — Whiting School of Engineering

Expected 2026

Master of Science in Computer Science (In Progress, Remote)

Boise State University

Aug 2018 - May 2024

Bachelor of Science in Computer Science

Minor in Applied Mathematics

Archbishop Riordan High School

Aug 2013 - May 2017

High School Diploma

Skills

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