Hello, I'm
Woojoo Song
Backend and data engineer who builds things people actually use.
About Me
Woojoo Song
Data Scientist · Backend Developer
Penn State University
B.S. in Data Science
Education
Penn State University
Expected Dec. 2026Computational Data Science
Certifications
Lean Six Sigma Green Belt (CSSC)
Skills
Languages
- Python
- Java
- SQL
- C++
- R
Frontend / Mobile
- React Native
- Flutter
Backend / Database
- Node.js
- Firebase
- Supabase
- PostgreSQL
Database
- Firestore
- MongoDB
Data / Machine Learning
- Pandas
- Scikit-learn
- Spark
Experience
People Link One (PLO)
Jan. 2025 – PresentState College, PA
Vibe Coding Instructor
Sep. 2026 – PresentTeaching club members to build working apps with AI coding tools, focusing on breaking down problems, reviewing generated code, and debugging.
Development Lead, Sell&Go
Dec. 2025 – May 2026Built the backend and database from scratch and led a 5-person dev team to launch a campus marketplace in 5 months.
President
May 2025 – May 2026Led a 20-member student development club, managing priorities and people across concurrent projects and shipping campus apps to 200+ active users.
Software Developer
Jan. 2025 – PresentBuilt the Firestore backend, real-time chat, and map navigation for TAGO; currently building the image transmission pipeline for an AI drone system.
Slam
Jun. 2026 – Aug. 2026Backend Developer Intern · Seoul, South Korea
Designed the database and access control for an AI video platform on a 3-person team (Node.js, Supabase). Caught two pre-launch security gaps: a row-level security hole that let suspended users reverse moderation actions, and a table-level grant silently overriding a column REVOKE on user emails.
2nd Infantry Division
Aug. 2022 – Feb. 2024Senior KATUSA (Sergeant) · Camp Casey, South Korea
- Led and mentored a 25-member squad, fostering teamwork and accountability in high-pressure environments.
- Coordinated training schedules, logistics, and mission planning, ensuring smooth execution under dynamic conditions.
- Developed cross-cultural communication skills as a senior KATUSA, bridging U.S. and Korean military personnel.
- Strengthened problem-solving and leadership abilities, later applied to academic and entrepreneurial projects.
Projects
Selected works
Highlights
TAGO
Ride-matching app for Penn State students heading to the airport, published on the App Store. I designed the Firestore schema and built real-time chat and Google Maps navigation.
Sell&Go
Campus resale marketplace with 200+ active users. As development lead, I built the backend and database from scratch and led a 5-person dev team through listings, in-app chat, and map features.
Disaster Tweet Classification
Fine-tuned DistilBERT to classify disaster-related tweets from a Kaggle dataset, reaching 0.81 validation F1.
More Projects
Consumer Loan Default Prediction
Cleaned 150K consumer credit records from Kaggle's "Give Me Some Credit" dataset, tracing extreme debt-ratio outliers back to missing income data. Built Logistic Regression and XGBoost classifiers reaching 0.87 AUC-ROC, and used SHAP to confirm credit utilization and delinquency history as the top risk drivers.
AI Drone Control System
A drone that runs AI inference on camera images to guide flight. I built the image pipeline: a Raspberry Pi camera wirelessly streams images to a GPU machine for inference, with a Pixhawk handling flight control. Pi-to-computer transmission is tested; full flight testing is next.
UniGuide AI
University info chatbot. I proposed switching data collection from manually documenting the school website to web crawling, and set the cleaning rule to keep only academic-related Q&A pairs. The team fine-tuned the model on this data.
Call of Duty Gameplay Analysis
Cleaned gameplay data, ran inferential modeling, and built logistic regression and XGBoost classifiers in R Markdown.
AiD
An intelligent web application designed to provide automated insights and AI-driven solutions tailored to user needs.
Web Scraper for Fortune 500 Companies
A custom web scraping tool developed for an academic research program. It automates data collection, parsing, and extraction from various online sources for robust data analysis.