I am a FullStack Web developer who designs products with empathy and a deep understanding of users. Rather than simply building interfaces, I focus on the context in which users experience a feature.

When making technical or architectural decisions, I ask myself "Is this the most meaningful choice for users at this stage?"

Beyond frontend development, I explore backend and DevOps to better understand the web ecosystem and build more holistic solutions. To me, great technology is not just about writing code — it’s about creating experiences that truly resonate with people.

Intensive full-stack training program focused on building production-level web services.

Autonomous driving simulation using NVIDIA Isaac Sim (RGB-D perception)

• Built data processing pipelines
• Worked with simulation-based AI environments

Frontend-focused development program

Startup-oriented IT club

• Developed web services in a collaborative environment

University web development club, Frontend Lead

Elice School & University SW Program

• Mentored students in algorithms and web development
• Designed beginner-friendly coding curriculum

Production-like ticket reservation simulator

Next.js MSA Docker CI/CD NCloud

• Designed MSA-based queue & reservation architecture under limited server constraints
• Applied ISR for frequently updated performance listings to reduce server load
• Optimized CI/CD in a monorepo by detecting changed packages via shell scripts
• Designed scalable NCloud infra (LB, Auto-scaling)
• Improved FCP/LCP/CLS through Lighthouse analysis and image optimization

Multi-user web-based OS simulation

WebSocket System Modeling ÒS`

• Modeled kernel–user space architecture and abstracted system calls via HTTP /syscall
• Implemented virtual file system using Node.js fs
• Built real-time multi-user sync (cursor/window/memo) with WebSocket + in-memory state
• Reduced sync latency by throttling mouse events and delayed DB persistence
• Integrated AI terminal using NAVER CLOVA function calling

Map-based accommodation booking service

PostGIS Performance Optimization UX Improvement

• Implemented viewport-based real-time map search
• Applied R-Tree spatial index → improved query speed from 5–10s to 0.02s
• Designed race-condition test cases to prevent double booking
• Improved UX based on Airbnb UI analysis

Instagram-like web platform (SSR + SPA hybrid)

SSR Node.js Webpack Cluster

• Built custom HTTP server and reverse proxy using Node.js net
• Implemented SSR without template engines
• Designed multi-process server using Node.js Cluster module
• Configured Webpack manually (MPA, Tree-shaking, Babel)

• Email: flowersayo@gmail.com
• Blog: https://www.tistory.com/