I applied through a recruiter. I interviewed at Lightmatter (Boston, MA)
Interview
They have a very frustrating interview process.
After the initial screening (which may or may not happen twice), they have a take home programming quiz where you're probably going to spend hours on random things like setting up a git repo and a build system, after you create an account on their favorite cloud git service.
Then they have an additional interview with some engineer, which they'll totally ignore the programming quiz.
Finally, you'll do a day's worth of yet more interviews where you'll talk with more engineers and the founders.
Scheduling is a mess and there is a total disregard for your time.
There are other companies that will value you more.
This was the worst interview process of my life. The people were generally nice but the logistics and the last minute changes were not only annoying, they reflected a general lack of respect for the candidate's time. Maybe, MIT should have included some mandatory Humanities subjects that would have made the founders a little less mechanical ;)