Pros
I've been here for over a year now and am very happy. The work is good, the people are nice, there is an emphasis on office community, and there are nice perks (monthly socials, catered lunches, a super convenient gym membership, et c.). The employees tend to be on the younger side which I think is in-line with Brighterion's practice of hiring less seasoned employees in the hopes of developing them professionally. To this end, the workload is reasonable and mostly stress-free. It's been very rare that I've needed to stay late, but it's not uncommon for employees to work into the evenings for their own reasons (avoiding BART crowds, coming in a little late, enjoying what they're working on). It's one of the best places I've ever worked (I've been professionally writing software for about 7 years).
Cons
I have nothing of substance to complain about. It's worth mentioning that Brighterion isn't for everyone though. Here are just style and culture notes that might surprise developers who are more accustomed to the fast and loose development practices that many startups allow. Brighterion mostly feels like working at a mature startup, but sometimes it feels like working for a much larger company. If high visibility into the project plan or needing lots of context for working on a component is part of a person's work style then this might not be the place for them. Specialization/Siloing is a normal part of development and most components are accessed through interfaces without ever having access to their code (it's worth mentioning that there is documentation available for everything). The lock-downs in place for PCI compliance are strange at first but turn out not to limit productivity. Very few 3rd party libraries are used or needed.