some box under ike's desk (2013)

My first real tech job was as a test engineer at edX. I was hired¹ in 2013, a few months after Harvard and MIT invested $60 million in the company. This was at the height of excitement for massively open online courses (MOOCs). In June, Anant Agarwal, then president of edX, was interviewed on The Colbert Report, and the influx of traffic promptly took down edx.org. I think there were a handful of courses on the platform that first year, but it quickly grew to hundreds, then thousands.

I spent the first few months adding unit tests for every problem type (multiple choice, code input, and many others). One of these was called “symbolic response”. A student would enter some algebraic expression, and symbolic response would check if it was equivalent to the correct answer. So if the correct answer was 2x+3y, then the code would accept something like 3y+2x or x+x+2y+y.

Buried deep in the code for symbolic response was an HTTP request to a subdomain of mitx.mit.edu. As I remember, the request only happened for certain inputs, or maybe certain prompts. It had something to do with converting the algebraic expression to MathML. The code was contributed by a professor at MIT, and someone had added a warning at the top of the file: “Dark code.” To this day, I’m not sure if any courses on edX actually used this.²

So I did the test engineer thing and mocked the HTTP response. But I was curious and asked about it. What server was this code calling?

Someone who had been there a while told me, “Oh, that’s just some box under Ike’s desk.”

Now I think he was probably joking, but at the time I believed it. That edX depended on a computer under a professor’s desk at MIT.