Personally I've never worked at a place where my input has been so highly valued and I'm not particularly high on the totem pole (and I work remotely to boot). It doesn't matter. Everyone has something to contribute and everyone's contributions are equally valued. I've learned an immeasurable amount in just a few months from the ridiculously smart people I get to work with. This is the smartest, most committed crew of people I've had the pleasure of working with. They're fun people too.
Maybe working for someone else isn't your thing, but if your circumstances require you to do so, there are few better places to work.
If anyone has any questions about what it's like working at Twilio, feel free to contact me directly at jsheehan@twilio.com or ask your questions here and I'll answer what I can.