Sr System Admin

Have you worked on Firewalls?
Have you worked on Switches?
Have you worked on Routers?
Have your worked on Wi-Fi AP or controller?
If yes, What are they? Model and Firmware version running on them? What kind of work? Are you proficient in CLI or GUI? Have you upgraded firmware? Have you done failsafe restore on these devices?
Have you been through any IPS/IDS attacks? Have you setup IPSEC/GRE/SSL VPN tunnels? Have you involved in configuring BGP or any other dynamic routing protocol?

Knowledge on Virtualization? What level of it? (Beginner/Moderate/Advanced)
What could computing environments experience you have? What is your level of involvement in build the cloud environment? Have taken online backups/system images/
Email Server management experience?

Experience on working with Windows Servers, Desktops/Laptops? (Beginner/Moderate/Advanced)

Experience on working with Linux and Mac OS? (Beginner/Moderate/Advanced)

Experience on Storage and Data Backup?

Antivirus and Patch Management administration experience? What are they(list out)?

Experience with Ticketing system and Monitoring systems like (Nagios)?

Knowledge on ISMS and ITIL processes will be an added advantage.