The interview process began with a personal email from one of the senior developers on the team. From there we had a quick initial phone screen and then a pair coding phone interview using a shared screen tool. The problem was an actual problem that had existed in the code base and felt much more tangible and practical than some code sample interviews.
From there the interview proceeded to an onsite interview in the San Francisco office where I spent the entire day meeting with and being interview by different members of the team. This included a large system design interview, and pair coding interview in Rails, leadership and strategy / vision questions.
Throughout the process everyone from Teespring was extremely helpful and patient and real. At every point people were passionate about what they did and were more interested in the making sure the process was right for me.