Pros
Slack is a company filled with hard-working, caring, and hilarious people that are committed to doing great work. You'll find that you are welcomed to the company with open arms and any team you join makes sure that your transition to the company is as smooth and enjoyable a possible. The problems that you work on are both challenging and fascinating, and the product itself is just such a pleasure. What I find most admirable about Slack, however, is their ongoing and renewed commitment to helping those less fortunate and fostering diversity within the company. Slack is one of the few companies in which I have seen a Black and Latino women make up a good portion of the engineering managers. It's inspiring and necessary. All in all, Slack is an amazing company. I am so lucky to work here.
Cons
As someone who is relatively new, I feel like I am not experienced enough to comment on any things Slack needs to improve yet.