I worked as an Application Operator (2nd lvl) in Hungary, Budapest (IBM Aviation - 4yrs, Vodafone - 3yrs).
Mainly we had 3 roles:
1, Proactive incident handler, event handler. We used monitoring systems for example: Nagios, HPOM, Zabbix.
2, Incident handler, reactive incident handling. HP manager, Jira, ServiceNow, Remedy
3, Task manager. Performed regularly daily tasks and checks. Executes changes in productive and test environments (Linux, Windows).