Pros
Slack has been a really unique experience. Slack is owned by Salesforce, but has not been entirely integrated into the corporate experience (though we trend closer to integration every month.) The developer experience has been strongly employee driven, and the engineers are very passionate about maintaining what makes Slack Great. The codebase is primarily Hacklang, an interesting PHP variant. I really hated it at first, but after having worked with it for some time, I find it relatively easy to write and follow. When you start, everyone is very understanding that it takes 6+ months to really get a full grasp on the language and our codebase. Using AI is encouraged but not explicitly required like at some tech shops. Coding LLMs are not necessarily great at Hacklang, but the more recent models have been getting better.
Cons
Creeping corporatization. Huge, hundred-to-thousands of employee meetings where absolutely nothing of any import is said. Massive priority shifts recently as the Agentforce bet flopped, and a revitalized push into agents.