Grammarly

Grammarly is a young company. Since it is profitable and growing, it is no longer a startup. This tells you a bit about its current focus.

Apart from that, there is an ambitious project goal. Having a noble and ambitious project goal does help motivation a lot, especially if you have a nice collection of young specialists around, which Grammarly does have.

There are some downsides as well. If you are looking for a developer position, there is not much space for promotion. Positions like VP of Engineering and Team Lead are usually filled via recruiting rather than promotion. A big part of the development team is outside the US, so consider all the cons if that as well.