API Guy.

He has a serious regex problem.
Regexes are never easy to read, but the ones he uses just take the cake. They're either blatantly wrong, or totally over-engineered garbage that somehow still lacks basic functionality. I think "garbage" here is a little too nice, since you can tell what garbage actually is/was without studying it for five minutes.

In lieu of an actual rant (mostly because I'm overworked), I'll just leave a few samples here. I recommend readying some bleach before you continue reading.

Not a valid url name regex:
VALID_URL_NAME_REGEX = /\A[\w\-]+\Z/

Semi-decent email regex: (by far the best of the four)
VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i

Over-engineered mess that only works for (most) US numbers:
VALID_PHONE_REGEX = /1?\s*\W?\s*([2-9][0-8][0-9])\s*\W?\s*([2-9][0-9]{2})\s*\W?\s*([0-9]{4})(\se?x?t?(\d*))?/

and for the grand finale:

ZIP_CODE_REGEX = /(^\d{5}(-\d{4})?$)|(^[ABCEGHJKLMNPRSTVXY]{1}\d{1}[A-Z]{1} *\d{1}[A-Z]{1}\d{1}$)|GIR[ ]?0AA|((AB|AL|B|BA|BB|BD|BH|BL|BN|BR|BS|BT|CA|CB|CF|CH|CM|CO|CR|CT|CV|CW|DA|DD|DE|DG|DH|DL|DN|DT|DY|E|EC|EH|EN|EX|FK|FY|G|GL|GY|GU|HA|HD|HG|HP|HR|HS|HU|HX|IG|IM|IP|IV|JE|KA|KT|KW|KY|L|LA|LD|LE|LL|LN|LS|LU|M|ME|MK|ML|N|NE|NG|NN|NP|NR|NW|OL|OX|PA|PE|PH|PL|PO|PR|RG|RH|RM|S|SA|SE|SG|SK|SL|SM|SN|SO|SP|SR|SS|ST|SW|SY|TA|TD|TF|TN|TQ|TR|TS|TW|UB|W|WA|WC|WD|WF|WN|WR|WS|WV|YO|ZE)(\d[\dA-Z]?[ ]?\d[ABD-HJLN-UW-Z]{2}))|BFPO[ ]?\d{1,4}/

^ which, by the way, doesn't match e.g. Australian zip codes. That cost us quite a few sales. And yes, that is 512 characters long.

How to punish new users to Linux when they type sl instead of ls