Backend Developer & DevOps Engineer from South Korea, with experience across NHN Cloud, Samsung Electronics, Nexon Korea, and Dongbu CNI.
I enjoy building reliable backend systems, cloud-native infrastructure, and deep observability stacks that actually survive production traffic.
- Java / Kotlin (Spring Boot, MVC, WebFlux)
- Node.js / TypeScript / JavaScript
- C++ (IOCP, high-performance networking)
- SQL & NoSQL (Oracle, SQL Server, MySQL, Cassandra, Redis)
- AWS (EC2, RDS, Lambda, Route53, NLB/ALB, S3, ACM, CloudFront, CloudWatch)
- Infrastructure as Code (Terraform)
- CI/CD with Jenkins, CircleCI
- Docker & docker-compose, Kubernetes
- Grafana · Prometheus · Loki · Jaeger · Mimir · Cortex - Fluentd · Telegraf · Consul
Java 17 · Spring Boot 3 · MVC · Oracle · MyBatis · JWT Security · Swagger
A production-like backend service with:
- JWT authentication (
/api/v1/auth/login) - RESTful APIs for user, service management
- Oracle DB integration through MyBatis
- Optimized Oracle schema with structured table design, indexing strategy, and query performance tuning
docker-composesupport for local Oracle + MinIO- OpenAPI docs included
🔗 https://github.com/choiis/Spring-WebServer-Oracle
TypeScript · Node.js · Serverless Image Processing · AWS Lambda · S3 · SNS · CircleCI
A Lambda that resizes images instantly on S3 uploads:
- TypeScript + serverless-framework
- SNS notification after resizing
- CI/CD pipeline using CircleCI
- AWS X-Ray for tracing and debugging
🔗 https://github.com/choiis/ImageResizer_AWS_Lambda
Kotlin · Spring WebFlux · Cassandra · Zookeeper · Grafana Mimir
Distributed monitoring system designed for large-scale black-box checks:
- API & TCP scenario workers running in parallel
- Measures DNS lookup, TCP connection, network latency
- Cassandra as metadata/config DB
- Zookeeper for distributed coordination and locks
- Metrics exposed to Prometheus/Mimir
🔗 https://github.com/choiis/black-monitoring-watcher
Terraform IaC · Multi-tier AWS Architecture
Defines a complete AWS environment through code:
- VPC, subnets, routing tables, NAT/IGW
- EC2 (bastion, app servers), RDS, Redis
- NLB + Route53 + ACM + Autoscaling Group
- Security Groups and IAM roles
- Architecture design included in Draw.io format
🔗 https://github.com/choiis/AWS-terraform
C++ IOCP Chat Server · SQL Server · Jenkins Pipeline
High-performance chat system:
- IOCP-based chat server, bot client, and console client
- SQL Server storage (schema included)
- Jenkinsfile for automated Windows builds
- Visual Studio project (x64, Release)
🔗 https://github.com/choiis/Cpp-IOCP-Server
Full Observability Stack · docker-compose
All-in-one monitoring lab:
- Grafana Mimir (long-term metrics)
- Prometheus (scraper + remote-write)
- Loki (log aggregation)
- Jaeger (distributed tracing)
- Consul (service discovery)
- Everything runs via
docker-compose up
🔗 https://github.com/choiis/Grafana-Mimir-Loki-Jaeger
- Java, Kotlin, C++
- JavaScript / TypeScript
- SQL (Oracle, SQL Server), CQL (Cassandra)
- Spring Boot, WebFlux, Security, Batch
- MyBatis
- Node.js (Express)
- jQuery
- serverless-framework
- Maven, Gradle, Ant
- Oracle, SQL Server, Cassandra, Redis
- MinIO, AWS S3
- AWS (EC2, RDS, S3, Lambda, CloudFront, Route53, ACM, ELB, CloudWatch)
- Terraform (HCL)
- Docker & docker-compose
- Kafka, Zookeeper
- Consul
- Kubernetes
- Git, GitHub, GitLab, SVN
- Jenkins, CircleCI
- Grafana, Prometheus, Loki, Jaeger, Mimir, Cortex, Consul, Fluentd, Telegraf
- Continuous learning of modern Java, Spring Boot, and Kotlin technologies
- Multi-VPC AWS architectures with Transit Gateway
- Migrating legacy backends to Java 17 / Spring Boot 3 / Kotlin
- Efficient relational database schema design and high-performance SQL tuning
- Deep observability pipelines (metrics + logs + traces)
- Serverless event-driven services
- GitHub: https://github.com/choiis
- Location: South Korea