resume

Professional Summary

  • Senior Fullstack Engineer with 4+ years building scalable B2C mobile and web applications at a leading Korean EdTech company (50K+ MAU). Expertise in React Native, Node.js, MongoDB, and AWS with proven track record delivering high-impact features that increased user retention by 40% and drove 25% premium subscription growth. Fluent in Korean (TOPIK 5) and English, with strong AI/LLM engineering capabilities. Award-winning engineer (2x Hero Awards) with rapid promotion from Level 2 to Level 4 in 18 months.

Technical Skills

  • Mobile & Frontend
    • React Native (iOS/Android), ReactJS, Next.js 15, React 19, TailwindCSS, Lexical Editor, EditorJS
  • Backend & APIs
    • Node.js, FastAPI, Django, Express.js, RESTful APIs, WebSocket, Socket.io
  • Databases
    • MongoDB, PostgreSQL, MySQL, Redis, Firebase, Supabase, Pinecone (Vector DB)
  • Cloud & DevOps
    • AWS (Lambda, ECS, S3, EC2, EventBridge), Docker, GCP, CI/CD, Serverless Architecture
  • Cross-Platform
    • React Native, Electron, Chrome Extensions (Manifest V3), PWA, Desktop Apps
  • AI/ML
    • LangChain, LangGraph, OpenAI API, Whisper, RAG, Vector Embeddings, Prompt Engineering
  • Languages
    • Korean (Fluent - TOPIK 5), English (TOEFL 111, IELTS 7.5), Luganda (Native)
  • Programming
    • Python, JavaScript / TypeScript, C++, SQL

Professional Experience

  • Jul 2025 - Sep 2025
    Technical Founder
    HoverNotes (AI Video Note-Taking SaaS) | Remote, United States
    • Founded and led technical development of privacy-first AI video note-taking platform and grew it to over from $0 to $1100 MRR in 4 months
    • Full-Stack Architecture: Built three-tier system (Chrome Extension + Next.js 15 Web App + Python AI Backend) with React 19, TypeScript, FastAPI, LangGraph agents, and Docker
    • Privacy Innovation: Implemented local-first architecture with direct Obsidian vault integration and zero cloud storage
    • Universal Video Compatibility: Engineered advanced video detection working across YouTube, Udemy, LinkedIn Learning, Bilibili, and all major platforms
    • AI Integration: Built multi-modal processing with real-time streaming note generation using LangGraph reasoning agents
    • Global Reach: Developed 45+ language localization with culturally-adapted AI note generation and phased market rollout strategy
    • Tech Stack: Next.js 15, React 19, TypeScript, PostgreSQL, Drizzle ORM, Stripe, Supabase, Tailwind CSS, Docker, Python, FastAPI, Langchain, AWS (EC2, Route53, S3, Lambda)
  • Jan 2025 - Sep 2025
    Senior Full Stack Engineer (Freelance)
    GoGymi (EdTech SaaS Platform) | Remote, Switzerland
    • Led full-stack development of TexTutor, an AI-powered educational SaaS platform for Swiss teachers and students
    • Full-Stack Architecture: Built complete platform using Next.js 15, React 19, PostgreSQL, TypeScript with comprehensive responsive design
    • Billing & Monetization: Implemented Stripe subscription system with multi-tier plans, free trials, and automated workflows
    • Multi-Language Platform: Delivered internationalization supporting 5 languages (EN/DE/ES/FR/IT) with localized billing
    • Authentication & Security: Built complete user management with email verification, password reset, and secure session handling
    • Rich Features: Implemented Lexical editor with collaborative features, LiveBlocks integration, and PDF export capabilities
    • Tech Stack: Next.js 15, React 19, TypeScript, PostgreSQL, Drizzle ORM, Stripe, Supabase, Tailwind CSS, Docker
  • Jan 2024 - Jun 2025
    AI Engineer & Team Lead (Level 4)
    Bebridge Inc. (Slid - EdTech Platform, 50K+ MAU) | Seoul, South Korea
    • Led AI innovation transforming Slid into industry-leading AI-powered educational platform with 50,000+ monthly active users
    • Mobile App Development: Spearheaded React Native iOS/Android app launch with server-side video processing, increasing user base by 21% and mobile retention by 40%
    • AI Auto-Notes Pioneer: Built end-to-end LLM/Whisper-based auto-notes from video, increasing videos opened by 12% and overall retention by 25%
    • Cost Optimization: Achieved 60% API cost reduction through intelligent buffering and multi-provider optimization
    • Server-Side Video Processing: Developed FFmpeg-based screenshot solution on AWS Lambda overcoming mobile platform limitations
    • AI Agent Systems: Built LangGraph multi-agent pipeline for transcript correction with custom reasoning tools
    • Backend Innovation: Reverse-engineered YouTube video delivery for direct URL access, enabling mobile processing at scale
    • Tech Stack: React Native, Python, FastAPI, AWS Lambda, EventBridge, S3, FFmpeg, LangGraph, OpenAI/Whisper APIs
  • Jun 2023 - Dec 2023
    Senior Software Engineer (Level 3) - R&D Team
    Bebridge Inc. | Seoul, South Korea
    • AI Sliddy Chat (Industry First): Built AI chat for notes before Notion AI, using LangChain, Pinecone vector DB, and streaming responses
    • Semantic Search: Implemented RAG-based search increasing session duration by 25%
    • LLM Video Summarization: Built scalable event-driven cloud engine achieving 1,500 MAU and 25% weekly retention
    • Cost Reduction: Reduced summarization costs by 40% through result caching and API optimization
    • Performance: Improved summarization speed by 66% via parallel processing and lazy evaluation
    • Universal Export: Built multi-format export (Word, PDF, Markdown, Notion) with 96% accuracy, reducing support by 75%
    • Open Source: Contributed to LangChain, Vercel AI SDK, and Quivr
    • Recognition: Awarded Hero Award 2023, promoted to Level 4
  • Jun 2022 - May 2023
    Full Stack Engineer (Level 2)
    Bebridge Inc. | Seoul, South Korea
    • Real-Time Transcription: Pioneered WebRTC → Socket.io → Google Cloud Speech STT, increasing premium subscriptions by 51%
    • Stack Overflow Impact: Solution helped 5,000+ developers with WebRTC/STT implementation
    • Cost Optimization: Achieved 90% transcription cost reduction through provider evolution (Whisper → Google → Groq)
    • Authentication System: Designed cross-platform auth using AWS Cognito for Web, Chrome Extension, Mobile (React Native), and Desktop
    • Payment Integration: Built Stripe + Payple multi-gateway system with 35% checkout improvement and 98%+ success rate
    • Cross-Platform Development: React Web App, React Native Mobile, Electron Desktop, Chrome Extension (200+ commits)
    • Performance: Reduced load time by 57% through lazy loading and optimization
    • Open Source: Contributed to EditorJS and Redux Toolkit
    • Recognition: Awarded Hero Award 2022, promoted to Level 3

Education

  • March 2019 - February 2023
    Bachelor of Science in Electrical and Electronics Engineering
    Korea University, Seoul
    • GPA: 4.02/4.5 (Magna Cum Laude)
    • Publication: 'Responsible Music Genre Classification using Interpretable Model-agnostic Visual Explainers' in Springer Nature Computer Science Journal (4th ICDSA 2023)
    • Scholarships: Global Korea Scholarship (2018-2023), Ugandan Government Scholarship (2017)

Awards & Recognition

  • 2022, 2023
    • Bebridge-Slid Hero Award (2 consecutive years) - Top performer company-wide
  • 2022 - 2023
    • Rapid Promotion: Level 2 → Level 3 (2022) → Level 4 (2023) in 18 months
  • July 2020
    • Korea University Academic Excellence Award
  • 2019 - 2020
    • Korea University Dean's List (3 semesters)

Open Source Contributions

  • 118K ⭐
    LangChain
    • Framework for LLM applications
  • 25.1K ⭐
    Editor.JS
    • Block-style text editor
  • 11.1K ⭐
    Redux Toolkit
    • Official Redux toolset
  • 18.7K ⭐
    Vercel AI SDK
    • AI-powered streaming UIs
  • 18.9K ⭐
    MemGPT
    • LLM agents with long-term memory
  • 13.5K ⭐
    Pytube
    • YouTube video downloading library

References

  • Junghyun Park
    • CEO & Founder, BEBRIDGE INC.
    • Seoul, South Korea
    • LinkedIn Profile
    • Direct supervisor during tenure at Bebridge Inc. (Slid platform)
  • Beelee Chua
    • Associate Professor, Korea University
    • Seoul, South Korea
    • LinkedIn Profile
    • Academic supervisor and research mentor