A recruiter at Slack reached out to me, and I scheduled a call. We talked about my current role and past experience, plus what I was looking for in a new role.

Normally, the next step would have been to start working on a take-home exercise, but I expressed that I wasn't doing that until I thought I might be a fit for the company.

I was given the opportunity to schedule a call with an engineering director, where we talked largely about the company culture and what Slack was working on, as well as answering some questions I had about company structure and makeup.

I then moved forward with the take-home exercise. The recruiter told me that, as a general guideline, it should take 3-4 hours, though they give you a week to do it. I certainly couldn't have finished it in 3-4 hours and ended up taking about 8-10 on it. I submitted what I had at that point instead of adding all the bells and whistles to the code; it worked and did what was asked.

A few days later, I got a rejection email without any feedback. I'm not really sure what they were expecting or why what I provided didn't meet the requirements, at least for a follow-up conversation. I have a lot of theories, but without feedback, I really don't know what was wrong with what I provided. The challenge itself isn't a difficult one, though it's something you could spend 40 hours or more on getting perfect. It's difficult to tell when to stop working on it.

I should note that I was told that the take-home exercise is the only coding done during the interview process. I assume that means there aren't any whiteboard coding sessions for the on-site.

It's a take-home exercise; I won't ruin the surprise.