• Despite Slack's diversity PR, some women and minorities still experience horrible things/sexism/lesser treatment there just like any other tech company. There's more than one case of a perpetrator not only not being punished because of incidents but being promoted. Internal surveys continually reflect the dissatisfaction from URMs and virtually nothing is done. It feels awful when the company is telling a story externally that is divorced from the realities many employees experience internally.
• Senior leadership is extremely hit or miss. You're as likely to find inspiring leaders as you are to find people solely focused on building their personal brand/driving readership to their blog instead of doing any real work.
• There are management chains completely devoid of accountability, where a bad manager reports to and is close with a bad manager who reports to and is close with a bad manager… This is as demoralizing for direct reports/peer managers as it sounds.
• Your Slack experience is highly dependent on which department/team you're a part of e.g. someone in CE or Design is much more likely to report having a far better experience than someone in Marketing or Product, but it also varies highly from team to team within each department. Do your due diligence on the team you're joining.
• The monolith of a codebase has finally caught up to product/engineering. Everyone's heard about the recent weeks' long code freeze but development velocity has indeed slowed to a snail's pace. With more and more large enterprise customers coming in, a rumored IPO, etc, it's unlikely this will turn around in any substantial way. This is extremely tough if you work in Product/Design/Engineering.
• Slack's culture is "too nice" — people tend to be passive-aggressive and avoid difficult conversations/feedback. Poor performers who make it past 3-6 months are almost never managed out. The foundational values of the company like Empathy/Courtesy were well-intentioned but not fully thought out and the consequences can be felt now.
• The reward for doing well is typically being driven to burnout — many high performing employees are barely making it to their 2 or 3 year marks, let alone 4 years or beyond.