Pros
In Built-ID I worked with like-minded group of people that share the same goal – building a social-impact product that helps both the clients and end customers. I worked as part of the remote development team, while working closely with the management team to deliver new components for company's main product. During my few years at Built-ID I worked closely with different employees of the company – from the development team, over management and accounts, media and PR. Working in a startup can sometimes be stressful, but during my time at Built-ID I didn't have a single bad experience. On the contrary. I was personally in a bad emotional phase (with my ex-wife not allowing me to see my kid) and everyone at Built-ID was super helpful and really invested in making my time there much easier.
Cons
Like in every startup, working at Built-ID can be hectic at times but if you have a can-do attitude and don't accept no for an answer – you'll do just fine :).