Youngjun Yoo

I'm a

About

Hello! 👋 My name is Youngjun, but I go by Jun! I’m currently a junior at Purdue University, studying Computer Science 💻.
My current interests lie in web development, operating systems, distributed systems, and information security.
I'm open to both software engineering internship and systems software research opportunities in summer 2025!

Profile Image

👨🏻‍💻 Software Engineer with a Passion for Running 🏃🏻

Focusing on Software Engineering, Systems Software and Security

  • Location: West Lafayette, IN
  • Email: yoo156@purdue.edu
  • Major: Computer Science
  • Grade: Senior

This semester, I had the privilege of serving as the Team Lead for the Rebuilding Together East Bay Network (RTEBN) project with @Hack-the-Future, a Purdue student-led initiative. I'll continue leading this project in the upcoming semester, focusing on the development and deployment of a revamped website to support RTEBN's mission of community rehabilitation.

My academic journey includes experience as an Undergraduate Teaching Assistant, guiding students in core courses like Systems Programming and C Programming. Next semester, I’m excited to continue to serve as a TA for Information Systems and C Programming.

Last summer, I completed my third internship as a Software Engineering Intern at @Fasoo, South Korea's leading data security firm, further strengthening my expertise in software engineering and security—a field I've been passionate about since my first internship in 2021.

Beyond the world of tech, I stay active through running, lifting, and playing soccer—Go Red Devils! 🔴 Recently, I've also become a fan of attending basketball and football games. The photo on the left is from the Nebraska vs. Purdue game, which was an unforgettable experience (even though we lost!). Looking forward to catching more games this year! 🏀🏈

Skills

Programming Languages, Databases, Frameworks, & Tools.

Python 95%
C/C++ 90%
SQL 95%
Java 90%
JavaScript/TypeScript 85%
HTML/CSS 75%

Projects

A collection of my works, big and small 🌟

  • All
  • Course
  • Personal
  • Corporate

Mobile: Tap images for view options

Volunteer Management

React.js. Vite, Tailwind CSS, FastAPI, SQLite, SQLAlchemy, Netlify, Render

BoilerDate

React.js. Express.js, Material-UI, MongoDB Atlas, Render, Netlify

BoilerPlate

TypeScript, React.js. Next.js, Tailwind CSS, Firebase, Vercel, OpenAI API

PyFlaGoat

Python · Flask · SQLite3 · JavaScript · HTML · CSS

4Cast Weather

JavaScript · HTML · CSS

Javagram

Java

Spider Sense

Python · BeautifulSoup · NLTK · Flask · HTML · CSS

HTML Parser

C

ABGScraper

Python

Resume

A brief list of things that I've been up to in the past few years. You can view my official resume here.

🎓 Education

Bachelor of Science in Computer Science Honors

2020 - 2026 (Projected)
(Military Leave of Absence: Sep. 2021 - Jun. 2023)

Purdue University, West Lafayette, IN

GPA: 3.80 / 4.00

Relevant Coursework

  • CS 18000 - Problem Solving and Object-Oriented Programming
  • CS 19300 - Developer Tools
  • CS 18200 - Discrete Mathematics
  • CS 21100 - Competitive Programming I
  • CS 24000 - Programming in C
  • CS 25000 - Computer Architecture
  • CS 25100 - Data Structures and Algorithms
  • CS 25200 - Systems Programming
  • CS 30700 - Software Engineering I
  • CS 34800 - Information Systems
  • CS 35100 - Cloud Computing
  • CS 35400 - Operating Systems
  • CS 38100 - Introduction to the Analysis of Algorithms
  • CS 48900 - Embedded Systems
  • STAT 41600 - Probability

Relevant Courses in the Current Semester

  • CS 35200 - Compilers: Principles and Practice

💻 Professional Experience

Software Engineering Intern - AI, Frontend

Summer 2024

Fasoo Inc., Seoul, South Korea

  • Developed a real-time voice-to-note solution using React and WebSockets, integrating STT and LLM to process responses for 300+ active daily users.
  • Implemented a TTS platform using OpenAI TTS, enabling bi-directional voice communication with Claude 3 Haiku LLM, increasing user engagement by 65% through dynamic voice interaction and multilingual support.
  • Implemented audio transcription and diarization with WhisperX, achieving 95% accuracy on 2-hour audio files.

Software Engineering Intern - Frontend

Summer 2023

Fasoo Inc., Seoul, South Korea

  • Engineered new features in the internal TypeScript/React/Redux-based project management system by building reusable frontend components for tracking project status, creating tasks, and updating the overall progress
  • Developed and integrated a real-time markdown renderer with React, transitioning from manual formatting to markdown-based documentation with live preview, enhancing collaboration and boosting productivity by 40% for 300+ employees.

Software Engineering Intern - Security, Backend

Summer 2021

Fasoo Inc., Seoul, South Korea

  • Created a deliberately insecure Flask application to test Sparrow, a static/dynamic application security testing solution.
  • Augmented Sparrow’s static application security testing (SAST) suite with new ground truths, mitigating 90% of obfuscated OWASP Top 10 security risks in Flask WebGoat, surpassing the detection capabilities of external tools.
  • Implemented Flask logging, enabling real-time on-screen display of deserialization for insecure Linux commands.

🚀 Campus Involvement

Purdue Hack the Future

Fall 2024 - Present

Team Lead

  • Leading a 10-person team in developing and deploying a revamped website for Rebuilding Together East Bay Network (RTEBN), ensuring stakeholder alignment.
  • Organized weekly meetings, served as the primary communication point with stakeholders, and utilized Agile methodology for project management.
  • Acted as Scrum Master, facilitating team collaboration and mentoring in React, Git version control, and design principles for effective project delivery.
Fall 2023 - Spring 2024

Frontend Developer

  • Developed a robust billing website for YWCA using React and Material UI, enhancing both user experience and operational efficiency.
  • Created a CSV file previewer that seamlessly integrates with the new billing frontend, offering efficient parsing and instant display of data in a well-organized table, tailored for non-profit billing management.
  • Automated the generation of personalized vendor bills from CSV uploads, facilitating direct PDF downloads and achieving a 65% reduction in bill processing time.
Fall 2020 - Spring 2021

Backend Developer

  • Worked in a team to develop large-scale software for NICHES Land Trust, an organization focused on conserving natural habitats in west-central Indiana.
  • Developed a full-stack web application that tracks items needing removal in parks, integrating geolocation to help volunteers navigate trails with interactive landmarks and waypoints.

✏️ Undergraduate Teaching Assistant

CS 34800 - Information Systems

Spring 2025

Purdue University Department of Computer Science

  • Spring 2025

CS 24000 - Programming in C

Spring 2024 & Spring 2025

Purdue University Department of Computer Science

  • Guided 300+ students on core C concepts (memory management, pointers, structs) through a course Q&A forum.
  • Participated in QA for assignments for 700+ students, graded assignments, and led weekly labs with 30+ students.
  • Evaluated code standards, specifically focusing on variable definitions, initialization, and scope detection to ensure adherence to quality standards.

CS 25200 - Systems Programming

Fall 2024

Purdue University Department of Computer Science

  • Conducted weekly lab sessions, assisting 100+ students in systems programming concepts and supporting malloc implementation, shell scripting, shell implementation, threads/mutex locks/spin locks, and web server projects.
  • Evaluated code standards, specifically focusing on multiple logical expressions to ensure adherence to quality standards.