
Shusei Yokoi
Data Scientist / Research Assistant
Data Scientist with a focus on trustworthy and interpretable AI. Currently pursuing an M.S. in Applied Data Science at USC and conducting trustworthy AI research at ISI.
I build data-driven solutions with strong software engineering skills and a business-driven mindset. I work end-to-end across the data science lifecycle, from defining business problems and analyzing data to evaluating models and deploying solutions that solve real-world problems.
— Turning Data into Smiles.
Experience & Education
ResumeResearch Experience
USC Information Sciences Institute (ISI)
Research Assistant
2026 – Present
USC Information Sciences Institute (ISI)
Research Assistant
2026 – Present
Bias by Prompt LLM Fairness | Python, ChatGPT, Claude, Gemini, Qwen
- Conducting research on trustworthy AI, focusing on fairness, bias, and reliability in LLM-based decision-making
- Designed controlled experiments to evaluate the effects of prompt framing on responses across LLMs, including ChatGPT, Claude, Gemini, and Qwen
- Identified early evidence that emotional prompt framing can alter LLM behavior, causing conclusion shifts in some models and reduced confidence in others
Professional Experience
Datify
Founder / AI Product Developer
2025 – Present
Datify
Founder / AI Product Developer
2025 – Present
Founded and Developed an AI-powered Solutions | R, Python, Swift, Azure OpenAI
- Founded Datify to build AI-powered products that help people improve their lives through personalization
- Developed HealthSync, an iOS AI health advisor app integrating Apple HealthKit and Azure OpenAI GPT-4o to deliver personalized health insights from biometric and activity data
- Built data pipelines to extract biometric data from Apple HealthKit and convert them into structured summaries for AI analysis to generate dynamic, contextual health advice, helping users track trends and stay on target with personal goals
SoftBank
Data Scientist
2022 – 2024
SoftBank
Data Scientist
2022 – 2024
Gym Chain Health Data Analysis | R, SQL
- Analyzed 200,000 member records for a gymnasium company with 150+ branches across Japan.
- Identified a 3-month weight regain trend in younger members and developed tailored retention strategies.
- Implemented a notification service to re-engage inactive members, increasing re-engagement rate by 30%.
Software Development Team Productivity Analysis | SQL, Python, R
- Performed Difference-in-Differences analysis on ticketing system data to diagnose productivity bottlenecks.
- Found resource allocation inefficiencies and recommended more frequent ticket creation and resource optimization.
SoftBank
Technical Project Manager
2022 – 2024
SoftBank
Technical Project Manager
2022 – 2024
Led Application Development | AWS, Azure, JavaScript, GitLab, SQL, VoltMX
- Directed end-to-end development of a multi-platform office management system for teams in Vietnam, China, and Japan.
- Led UI/UX design, back-end architecture, testing, and cross-platform deployment.
SoftBank
Data Scientist Contractor
2020 – 2022
SoftBank
Data Scientist Contractor
2020 – 2022
Trade Area / Population Flow Analysis | Tableau, SQL, Python, R
- Led trade area analysis for Izumi Co. with 190+ malls under SoftBank's Smart City project.
- Built Tableau dashboards using GPS, demographic, and search data to uncover customer trends.
- Recommended targeted ads, in-store improvements, and loyalty strategies based on retention and regional growth insights.
AI Engineer | Python, SQL
- Developed a population inflow prediction model to optimize billboard advertising placement.
- Improved model performance through data engineering and feature design, achieving an AUC of 0.70.
ABC Cooking Studio
Data Scientist Intern
2020
ABC Cooking Studio
Data Scientist Intern
2020
EC Site Analysis | SQL, Python, R, Google Analytics
- Analyzed EC site traffic using Google Analytics and modeled sales patterns across product categories.
- Predicted product sales using a multilevel model with category-specific price elasticity.
Education
University of Southern California
M.S. Applied Data Science
Expected 2027
University of Southern California
M.S. Applied Data Science
Expected 2027
Focused on machine learning, trustworthy AI, LLM evaluation, and real-world data science applications.
California Polytechnic State University, San Luis Obispo
B.S. Business Administration, Information Systems / Minor in Statistics
2021
California Polytechnic State University, San Luis Obispo
B.S. Business Administration, Information Systems / Minor in Statistics
2021
Data Science & Statistics
Statistical learning, regression analysis, multilevel and mixed modeling, categorical data analysis, statistical computing in R, time series, forecasting, and model evaluation.
Programming & Systems
Python application development, database systems, ERD/UML, advanced SQL, systems analysis, SDLC, UI/UX requirements, project management, and blockchain development.
Projects

An agentic AI chatbot with RAG-based reasoning that answers my career related questions.

Shows that basic LLMs can change conclusions from the same loan data depending on prompt framing.

