Pros
The small company environment allows (and requires you) to make large contributions to the overall companies success. Very little red-tape or bureaucracy to get your ideas heard. Plenty of opportunities to learn, and internal hiring is frequent. From a development standpoint you get to enjoy a full-stack position++ as there is a good chance you will get to delve into every aspect of development from backend to frontend to mobile to dev-ops to IT all in one day sometimes :) Regular team building, and a relatively laid back environment that stresses quality over deadlines. Lots of PTO. Toilet shaped logo is pretty rad too.
Kontras
Some rather outdated technologies are still in use, and the lack of budget/man-power doesn't allow for the team to tackle as much technical debt as they need to. Also, on a minor note, telling people you work for a "janitorial software company" tends to be difficult to explain to people as well.