Java development (Java 8+):
core java libraries;
SQL database (JDBC, Hibernate), MySQL 8+, PostgreSQL ;
NoSQL database (Redis, MongoDB);
Hadoop Distributed File System, proficiency with Spark’s RDDs;
Web: HTML, XML, JSON/ Frameworks: Spring Boot, Guice, Jersey ;
Build tools: Apache Ant, Maven, Gradle;
testing (JUnit, Postman);
Project Management and SCM: JIRA, Redmine, Git;
Python 3.+;
Docker;