Developer portfolios can be a bit of an enigma—how do you present yourself to employers without burying them in lines of code? A modern portfolio is more than just work samples, it’s also a statement of how you work.
Explain concepts important to validation of email addresses with regular expressions. Applies to most languages/tools that uses regular expressions.
Consider email address RFCs:
Look at HTML5 form input element (with type=email) regex pattern: