Here are some examples of the technologies that I support but I am very adaptable and have used a lot more than is listed here.
macOS Server 7 – 10
AFP, SMB, iChat, DHCP, DNS, OD, VPN, NetBoot
Microsoft Office 365
Synology NAS / QNAP NAS
Apple Business Manager, Mosyle MDM (and others)
Xserve, Xserve RAID, Promise RAID and other brands.
Windows NT, 2003,2008,2012,2019
Can setup basic server with AD and Mac Support.
Generally know my way around and comfortable with File Sharing, DHCP and DNS.
Unifi, Meraki, HPE, Netgear, Ruckus (networks and wireless)
Firewalls – Unfi, Watchguard, Draytek, ZyZel, SonicWall, etc…
Archiware Presstore (LTO, Amazon AWS)
Mac Active Directory Integration
Rumpus FTP/Web File Server
Microsoft Office apps (Mac/Windows)
FileMaker Pro / FileMaker Pro Server
Applescript
Adobe Creative Suite
Apple Keynote,Pages,Numbers
Font Explorer, Extensise Type Manager
Kerio Mailserver
A Microsoft Exchange alternative email server, calendars and contacts system. Works on macOS and Linux. Not really relevant anymore apart from having some knowledge to migrate from Kerio to Google Workspace or Kerio to Microsoft Office 365.
Linux [ Ubuntu Server, Ubuntu Desktop, Centos, RHEL ]
[ not an expert, I can install, connect, configure network settings. Examples of services I have installed and supported include: PHP, MySql, Apache, NGIX, DNS server, DHCP server, phpMyAdmin ]