Building a web application in an online environment that hosts a countless number of bad bots, malicious hackers, and other security threats can be complicated. A web application must first be built to be functional (easy enough, sort of), and to be secure. Ideally, security will be considered from the beginning, and then flaws will need to be addressed upon completion. So, if your organization handles customer data, which it almost certainly does, there are legal and regulatory compliance rules you have to follow.