What does the expression "so we can short it" means?

In this context, "short" is an abbreviation of "sell short".

Just as one buys a company's stock when one believes the stock price will go up, one short sells or shorts a company's stock when one believes the stock price will go down.

From Investopedia:

DEFINITION OF 'SHORT SELLING'

The sale of a security that is not owned by the seller, or that the seller has borrowed. Short selling is motivated by the belief that a security's price will decline, enabling it to be bought back at a lower price to make a profit. Short selling may be prompted by speculation ...

Thus, the author of the quote is saying, sarcastically and indirectly, that he believes companies which employ programmers who write 60-line functions will eventually go out of business.

The joke is that if you work in a company which employs 60-line-function-writing programmers, the author would like to know your company's name, so that he can profit from its inevitable doom.

_{Disclaimer: I have written 60-line functions. But maybe that's why I hang out more on EL&U than SO...}