I'm starting a project in which certain users will be giving their credit card numbers for online payments. I know how to deal with the web-application side of things, however I would like to get advice about what should be the IT considerations of maintaining such servers.
For starters, I guess I would rather keep the servers in-house and not use any cloud solution. But what in addition? What are the recommendations for firewalls or equivalent? Other systems to install? Other best practices?