Pros
Frontiers strives to fix the flaws in traditional academic publishing. It's a great place to be part of the cutting-edge in the publishing world: currently the 5th largest Open Access publisher in the world, and born digital - very tech-savvy and data-driven. The dynamic of the workplace is young and fresh - people are committed to their work and collaborate on ideas. Everyone is passionate about getting good research out into the world. Colleagues are friendly, and there are opportunities to advance, as well as good, paid internships.
Cons
The company's dynamism leads to constant innovation to improve. This means there's constant change built into working at Frontiers: if you're the kind of person who gets change fatigue, or who feels uneasy without a precise 5-year plan, this is not for you. However, if you like new challenges and have the energy to meet them, this can be a huge plus for you.