Slack reviews

4.0

77% would recommend to a friend

(1,095 total reviews)
avatar

Stewart Butterfield

88% approve of CEO

70% positive business outlook

Slack has an employee rating of 4.0 out of 5 stars, based on 1,095 company reviews on Glassdoor which indicates that most employees have a good working experience there. The Slack employee rating is in line with the average (within 1 standard deviation) for employers within the Informatique industry (3.9 stars).

Reviews by job title

1K reviews
5.0
Oct 27, 2025
Recommend
CEO approval
Business Outlook

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.

1.0
Oct 21, 2025
Recommend
CEO approval
Business Outlook

Pros

They give a lot of swag, work pace isn’t too hard, mid level people are generally nice

Cons

This company ruined my life and PIP’d me for taking time off to mourn. They took from me my passion for what I do and made me realize how quickly someone will throw you under a bus. Scheming managers. They did a soft layoff where they were forced to PIP a certain number of employees, I had never had a performance conversation or a negative comment and the manager fabricated evidence for a pip (including asking for advice, taking sick time when my dad died, and calling in a senior engineer during a high severity outage). I’ve personally spoken to multiple other engineers that had the exact same thing happen to them.

Viewing 22 - 24 of 1,095 Reviews

Glassdoor has 1,227 Slack reviews submitted anonymously by Slack employees. Read employee reviews and ratings on Glassdoor to decide if Slack is right for you.