VPN Servers Setup and Configuration

I need a skilled system administrator to create and configure VPN servers on both a Windows and Linux operating platform. Your task will primarily involve the implementation of client-to-site connections. A crucial part of this task is to establish a Certificate-Based Authentication system for all accessing users. I'm looking for someone with a strong background in system administration, specifically with experience in VPN setup and certificate authentication. Familiarity with both Windows and Linux systems is a must. Your role might include:

- Setting up the VPN servers
- Configuring the servers for optimal performance
- Implementing certificate-based authentication
- Ensuring secure client-to-site connections

Candidates who have successfully taken on similar projects will be preferred. Please detail any relevant experience when you put forward your quote.