Sysadmin for Infrastructure Setup

I need a skilled sysadmin to implement connections and services on our network infrastructure, that is made as follows.
- OPNsense running on a workstation: security settings and rules to be revised and improve
- Managed switches: VLAN setup and port security settings to be revised and update
- Windows Server 2019 already up and running DHCP and DNS servers (conflict risks policy to be assessed)
- WiFi routers/APs for networking to be integrated in the logical networks (VLAN, VPN, etc.)
- 10 local users and 5 remote users
- 3 industrial PLC devices to be accessed both via LAN and VPN

Ideal skills and experience:
- Previous sysadmin experience
- Proficient in OPNsense, managed switches, and Windows Server
- Strong English communication skills
- Immediate availability