I'm a security engineer, I can build it. What should I build to make a lot of money?

Hey all, I'm a security engineer and I love building things. I've been working on a build to make a lot of money off of an app or software for a while now, but the ideas I've generated don't generate a lot of profit. I want to build something that can be sold and used widely.<br><br>So, what should I build? I believe this sub is a great place to share ideas and a lot of these ideas can be built as a security engineer and can be built to generate a lot of income.<br><br>Also, ideas don't have to be security related. I think that is important to mention because as a security engineer, I can be pigeon holed on what can be built. That being said, I do love building security related things so I am open to those ideas as well.<br><br>Thanks for your ideas!