We're a small, non-profit tech startup bringing a free, world-class education to anyone, anywhere.
Here's a testimonial we received last week:
I just want to say thank you a billion times to Khan Academy. My Geometry midterm was this Tuesday. I was worried, because I barely passed my Algebra one last year. Enter Khan Academy. It was great practice, as they had a good amount questions where you had to manipulate on screen variables, rather than just answer multiple choice questions. This stood out to me, as my school gives tests with these types of questions and no other review site i found had them. We got our scores back, and I was the only person in my class that got an A. It's not really an "inspiring" story, but hey, I figured I'd share it anyway.
Mia might not think so, but her story does inspire and makes me happy to go to work here. Every month we get hundreds of letters like this from people in all walks of life who are thankful for our free, high-quality educational content. Most of you reading this are familiar with Sal's videos, but we also have hundreds of videos by other teachers, partnerships with organizations like MoMA and the California Academy of Sciences, and a huge library of interactive exercises. Over 20 million math problems are done every week on our site.
A few things we're currently working on building right now:
– Major improvements to our iOS app to let students practice skills on the go (or in a classroom with iPads!) 
– Improved knowledge models so we can better know what you know and don't know 
– Infrastructure improvements to make the site more reliable and faster for our millions of visitors every month 
– Better tools for our content creators to allow them to make thousands of engaging, interactive exercise problems without knowing how to code 
You'll be part of a small team working alongside both "celebrity" devs (like jQuery creator John Resig and Google's first employee Craig Silverstein) and many more who you haven't heard of but who are also really awesome.
We're especially looking for mobile designers/devs but we have a handful of other positions open -- take a look and see if anything suits you.
Apply at https://www.khanacademy.org/careers and mention that you're coming from HN. Feel free to ask me here if you have questions about applying or about KA in general. Unfortunately we can't sponsor visas right now unless you're from Canada, Australia, or Mexico.