Strong knowedge of Linux (Redhat/CentOS 7/8 mostly)
Strong knowledge of Jenkins structure, pipelines and libraries.
Very good understanding of Networking in general
Automation/configuration management using Salt (mostly) or Ansible.
Cloud services (Mostly AWS but Azure and Google Cloud a plus)
Build systems (Apache Ant/Node/Maven/Gradle)
Git and versioning software
Messaging middleware. Specifically RabbitMQ and Kafka
SQL in general and DB2, PostgreSQL, MySQL specifically
NoSQL experience with MongoDB and Redis, others such as Cassandra is a plus.
TSDB (InfluxDB, Prometheus)
Monitoring tools such as TICK stack, Prometheus, Grafana
Being certified in Linux, VMware. Good knowledge of Windows Server is a plus