- Cryptography and Public Key Infrastructure : BouncyCastle, EJBCA CA and Sign Server
- Java Desktop Application : JavaFX, Swing
- Web Application : Spring Framework, Hibernate, Javascript, Bootstrap
- Web Service : REST APIs and SOAP Web Service.
- Database : MySQL, MariaDB, PostgreSQL
- OS : Ubuntu, CentOS, RedHat
- CI/CD : Github, Gitlab, Jenkins, Travis
- Cloud Platform : Google Cloud, AWS, OpenStack
- Containe : Docker, Kubernet
- Tools : Git and Maven
- Automation Testing : Selenium, SAST, DAST, OWASP
- Documentation : JavaDoc, Swagger