Hi, I'm Jaeyoon Lee
I'm an Information Interaction Design student at Yonsei University passionate about building scalable infrastructure, dynamic websites, and elegant server solutions that blend design principles with development.
Selected Works
Startup2022.08 ~ 2024.01
Slice
Reinventing Business Cards for the Digital Era
Developed a digital business card platform from the ground up, spanning five domains including frontend, backend, and cloud infrastructure.
- Next.js
- Nest.js
- Jenkins
- AWS
- Docker
- Redis
Side Project2024.07 ~ 2025.08
Braille Camp
Building a Math-to-Braille Translation Service
Led full-stack development across infrastructure, server, and frontend, collaborating with a visually impaired algorithm developer to streamline deployment and improve accessibility.
- Django
- Raspberry Pi
- Self Hosting
- Cloudflare R2
- Jenkins
🚀 Lift off with Slice
Click to view journey
Selected Works
Startup2022.08 ~ 2024.01
Slice - Reinventing Business Cards for the Digital Era
Developed a digital business card platform from the ground up, spanning five domains including frontend, backend, and cloud infrastructure.
- Next.js
- Nest.js
- Jenkins
- AWS
Side Project2024.07 ~ 2025.08
Braille Camp - Building a Math-to-Braille Translation Service
Led full-stack development across infrastructure, server, and frontend, collaborating with a visually impaired algorithm developer to streamline deployment and improve accessibility.
- Django
- Raspberry Pi
- Self Hosting
Development Blog
Automating Environment Variable Setup with AWS Secrets Manager in Microservice Architecture
Managing .env variables in a microservice architecture is challenging. Sharing secrets via Slack or Notion is insecure, and keeping local environment files in sync across a team of developers is a constant headache. Not to mention the confusion with test vs. production keys and environment switching.
Nov 30, 2025
Understanding Let’s Encrypt’s HTTP-01 Validation Flow (with Nginx & Certbot --webroot on Linux)
I run my Nginx server in a Docker container with Let’s Encrypt SSL certificates, but automatic renewals aren’t supported for Nginx containers in Docker.
Sep 13, 2025
Use Slack Commands to Trigger MongoDB Backups with API Gateway and AWS Lambda
Hello everyone! To add on to the previous MongoDB Backup Microservice guide, here’s a way to manually trigger a MongoDB backup using a Slack Command connected to API Gateway and AWS Lambda.
Jul 31, 2025
Back Up MongoDB Data Every Week with EventBridge & AWS Lambda
Hello everyone! Recently, I created a MongoDB microservice using AWS Lambda & EventBridge to back up data every week.
Jul 21, 2025
