If you can identify you're writing insecure code or building insecure apps you are just being lazy to do it proper way. Web security IMO isn't about learning a new thing, these are concepts that are part of the development flow.

Good resources to start with:

OWASP Top Ten Project https://goo.gl/yv6D4t

OWASP REST Security Cheat Sheet https://goo.gl/93VPKD