Hyobeom Han

React Native -> Flutter Migration

• Due to the poor quality of the React Native expo code developed by an outsourcing firm before the team joined, and the absence of employees experienced with React Native, we decided to switch the mobile app framework to Flutter because of unresolved minor bugs.

• Development of webview screens
• Implementation of communication between web and Flutter app by connecting Javascript Channels for using native features (such as push notifications, mobile device storage)

• Flutter
• Sveltekit

AWS Backend Server Restructuring

• Due to the unreasonable configuration of the AWS backend server structure set up by the outsourcing firm before the team joined, a restructuring of the server structure was deemed necessary.
• The major issue was that the celery, celery-beat, and redis services were set up as ECS services, and containers were set to increase as usage increased.
• In reality, the only cases where celery was used in the current service were for push notifications, SMS, and email transmission, and there was no need for a scheduler. Therefore, the celery and celery-beat services were migrated to AWS Lambda for cost efficiency and easier management.
• When more than two databases with the same functionality are used, the complexity of the system becomes unmanageable. Therefore, the redis ECS service was migrated to a single ElastiCache instance for easy resource scaling.
• The gunicorn service responsible for handling sync requests and the daphne service responsible for handling async requests were each configured with Fargate to minimize maintenance points.

• Writing and connecting Lambda functions
• ElastiCache service configuration, data migration, and backend connection
• Modifying Django and nginx code and updating each ECR image
• Creating ECS Fargate services and removing existing services
• Proxy configuration for gunicorn target group and daphne target group via load balancer

• AWS ECR
• AWS CLI
• AWS Lambda
• AWS ElastiCache
• AWS ECS
• Django
• Nginx

React Native -> Flutter Migration

• Due to the poor quality of the React Native Expo code developed by an outsourcing firm before the team joined, and the absence of employees with experience in React Native, and unresolved minor bugs, the mobile app framework was changed to Flutter.

• Development of webview screens
• Implementation of communication features between web and Flutter app by connecting JavaScript Channel for using native features (push notifications, mobile device storage, etc.)

• Flutter
• Sveltekit

• Development of a cooperative housing management app for Wooridong representatives

• Service planning
• UI/UX design
• AWS server environment configuration
• Writing Django backend code
• Writing Flutter frontend code
• Released and operated on the iOS Appstore and Google Playstore

• AWS EC2
• AWS RDS
• AWS ElastiCache
• Django + DRF + Celery
• Flutter
• Nginx

• Development of a Taekwondo equipment e-commerce app (outsourced)

• Client requirements analysis and participation in planning
• UI/UX design
• AWS server environment configuration
• Writing Django backend code
• Writing Flutter mobile app frontend code
• Writing Sveltekit web frontend code
• Released and operated on the iOS Appstore and Google Playstore
• Development of internal management page for orders and members

• AWS EC2
• AWS RDS
• AWS ElastiCache
• Django + graphene + Celery
• Flutter
• Sveltekit
• Nginx

Fix Please [03/2023 - 04/2023]

• Development of a landing page and MVP prototype for a house repair platform

• Development of a landing page
• Planning and operation of a prototype using KakaoTalk channel

• HTML
• CSS
• Javascript (vanilla)

Smarter Plus Customer Service [05/2023 - 09/2023]

• Development of an internal counselor web for customer counseling service

• Client requirements analysis and participation in planning
• UI/UX design
• Django Graphql Api design
• Development of internal counselor web screens
• AWS server configuration and operation

• AWS EC2
• AWS RDS
• AWS ElastiCache
• Django + graphene + Celery
• Sveltekit
• Nginx