Applied via Slack website. Received an email letting me know I was progressing to the next stage (and included a written task for completion). After this I received an email saying I was being progressed to a phone interview and to select my availability via a calendar tool. Despite selecting every business day that week, I received no reply and no call. I then received another email with the same instructions for the following week. Again, despite making myself readily available, I received no reply and no call. To be honest, at this point I would not proceed with Slack. As a company that boasts about it’s customer service, Slack needs to understand that potential and current employees are also “their” customers and in this day and age this sort of applicant experience is appalling.