If I'm reading that correctly, Segment was (is?) providing some people $8K per month for 3 months to work on open source projects. That's amazing! Here's a link to their 2017 application page: https://open.segment.com/fellowship
I suppose I should be spending more time looking out for this kind of thing. It's possible there is more money in open source development than I had previously considered.
It's a great scheme, and I applaud them for it, and it's a hike up if you're non-Senior, but for about 10%-20% of engineers I know it's a pay cut for 3 months. That's OK, you get to work on something awesome. Not bad, really.