Pros
ZI is very focused on its employees. I have found that everyone that I have connected with in the company from the highest to the lowest levels wants to help you move the company ball forward as well as your own ball forward. The company still has a start-up vibe in that things are fast-paced and pivot. For me I thrive in this environment. Be prepared to work hard in exchange for great benefits and a positive culture. I look for passionate people who are looking to make an impact and blaze new paths. That is a great culture fit.
Cons
I haven't experienced cons yet. I guess if someone is looking for a job to check-in and out of 9-5 daily then a fast-growing company is probably not the best fit. But if you like working hard to build something amazing then joining is a good fit.