Pros
The #1 pro and main reason each person joins Paradigm is the mission-driven work that Paradigm does with clients. This is great because it means your whole team and the entire company is focused on one goal when working with client companies. Other pros include great benefits (such as a 401k with employer matching), a startup environment (where everything may not be 100% built out, but that means you can take ownership of something and make it happen), and accessible leaders (I've been in startups and large corporations where it was all a lot harder to access the CEO or other leaders; leaders at Paradigm hold office hours and generally are always around for questions or discussions).
Cons
A pro is that it's a startup, but a con is also that it's a startup. That means that there are some policies and processes that aren't set up yet, or that there's a lot of iteration in building the approach to project execution or the "way" we do things. I think that some people thrive in environments like this, but others may prefer a place where everything is already built and setup.