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

Technical Founder

HoverNotes (AI Video Note-Taking SaaS) | Remote, United States | Jul 2025 - Present

• 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, Docker, Langchain, AWS (EC2, Route53, S3, Lambda)

Senior Full Stack Engineer (Consultancy -> Freelance)

GoGymi (EdTech SaaS Platform) | Remote, Switzerland | Jan 2025 - Sep 2025

• 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

AI Engineer & Team Lead (Level 4)

Bebridge Inc. (Slid - EdTech Platform, 50K+ MAU) | Seoul, South Korea | Jan 2024 - Jun 2025

• 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

Senior Software Engineer (Level 3) - R&D Team

Bebridge Inc. | Seoul, South Korea | Jun 2023 - Dec 2023

• 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

Full Stack Engineer (Level 2)

Bebridge Inc. | Seoul, South Korea | Jun 2022 - May 2023

• 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

Bachelor of Science in Electrical and Electronics Engineering

Korea University, Seoul | March 2019 - February 2023 | 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

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

OPEN SOURCE CONTRIBUTIONS

• LangChain (118K ⭐) - Framework for LLM applications
• Editor.JS (25.1K ⭐) - Block-style text editor
• Redux Toolkit (11.1K ⭐) - Official Redux toolset
• Vercel AI SDK (18.7K ⭐) - AI-powered streaming UIs
• MemGPT (18.9K ⭐) - LLM agents with long-term memory
• Pytube (13.5K ⭐) - YouTube video downloading library
• Vexa (1.5K+ ⭐) - Real-time multilingual meeting - transcription and streaming bots​
• Agno (19K+ ⭐) - Multi-agent AI framework, runtime and control plane​
• FastAPI (84K ⭐) - High-performance Python API framework

REFERENCES

Junghyun Park

CEO & Founder, BEBRIDGE INC.
Seoul, South Korea
📞 +82-10-4710-5607
Direct supervisor during tenure at Bebridge Inc. (Slid platform)

Beelee Chua

Associate Professor, Korea University
Seoul, South Korea
📞 +82-10-4196-2689
Academic supervisor and research mentor