One possibility for showing the projects off behind the firewall would be creating a intro/demo video of the systems - for new employee on boarding, but also yo

One possibility for showing the projects off behind the firewall would be creating a intro/demo video of the systems - for new employee on boarding, but also you could probably get permission from your manager or whoever to take a copy of the video home (or put online) to show family/others what you've been up to.