Java Senior Developer (+15 years experience) - backend development (Spring, JPA/Hibernate, myBatis, JEE, ...)
Web Developer (Flex, Angular) (+10 years)
Database Designer (+10 years) (Oracle, MySQL/Maria, DB2, Derby, Postgres).
TMA Expert
System Administration - Linux SuSE, Redhat, Debian/Ubuntu.
DevOps Engineer - Kubernetes, Docker.
Atlassian JIRA and Confluence administrator and plugin developer.

Much more to say but hey... you know the principal...