Pros
A fantastic product to work on. The engineering and product teams care very deeply about building a great product and it shows. The engineering organization is frequently directly in contact with customers and solicits feedback from them very early during product development. The day-to-day work is very engaging and projects are given as problems and not solutions. Once a project is started leadership generally gives additional time to iterate and improve solutions until they are better than 'good enough'. Furthermore, the company continually makes time to invest in improving its tools and technology. Like many smaller companies, career progression is self-driven and will require you to ask for additional challenges and opportunities and not wait for them to be given to you. I have this as a pro, because if you're a motivated ambitious person Sentry presents a ton of opportunity for personal growth.
Cons
The company has a shortage of process in a few aspects. The situation has been improving as new leaders have been brought in, but I find Sentry could be better at co-coordinating work across teams. Teams can be somewhat siloed and cross team collaboration relies on ad-hoc pathways and personal connections. While the leadership, and individual contributor rosters are well staffed the team lead/engineering manager layer of the company has been less well staffed.