The interview process starts with a couple of phone calls with two different hiring managers. One is an informal and informative conversation about Slack, and the other is a short technical screen where you are asked both behavioral and technical questions (no coding).
The next step is a 1-week take home project where you are asked to build a toy feature for Slack. There's nothing crazy about it, as long as you have a decent understanding of React. I ended up taking the full week, but others may only need a day or two to finish it. This is the only code you will write through the entire interview process.
The onsite comprised of four sections - one behavioral, two technical, and a hiring manager chat, before finally following up with a recruiter. This was where Slack left a really positive impression on me. I felt none of the usual pressure that comes with an onsite interview, largely due to the fact that there were no painful live coding sessions. The technical sections instead revolve around high level component design and web architecture as well as a short review of your take home project. The behavioral questions are fairly typical, perhaps centered around teamwork and collaboration.
Overall, to me the interview process felt "easy" in the sense that it wasn't stressful at all. As far as the technical portions go, if you deeply understand front end development best practices and browser technologies, you will have little difficulty tackling the problems presented.
