Pros
Slack for me is the best of two worlds: the excitement of a true startup, but with the financial stability of a large company that comes from having hundreds of millions of investment in the bank. This provides an environment of ceaseless forward momentum and opportunity to stretch yourself. There is not only an opportunity to put your stamp on things, but a necessity, as small teams try to achieve what is normally done by groups ten times their size at other companies. In general, your leadership will give you wide latitude and trust to get the job done as you see fit. If you are ambitious about your career, Slack is an open road.
Cons
Many people feed off the energy of a startup environment. If you don't, however, and instead seek stability and predictability, Slack will probably not be the dream employer for you. As a company that has achieved more in four years than other top tier tech companies have in ten years, change is constant here. If you have come from a large company like Google or FB, learning and development will feel different than what you are used to. You will find very little structured, classroom-style learning here, but you will learn on the job through being afforded opportunities to do things you otherwise wouldn't. Some may find this a little daunting.
