I made initial contact with their HR dept by applying online and having a friend who works at the company give my resume and cover letter to HR. They contacted me to schedule an interview at their headquarters in St. Louis, scheduling was very flexible and compensation for gas was provided. Upon arrival, I was sat in an office where I took 3 different tests. The first test was a mental alertness test. Second test was a physics-based mechanical aptitude test. The third test was tool recognition where you were given pictures of tools and you had to name the tool and list its use or function. The first two were timed tests. I was not interviewed by HR but by the engineer I will be working under. He was more interested in previous hands-on experience as well engineering and design experience. I brought a project portfolio which helped a lot in showing my previous projects. None of the typical strenuous interview questions were asked which was a relief. I was supposed to be interviewed by multiple engineers but the others were out of the office. Since I was one of the first interviewers, I was told that I should wait up to two weeks to hear back but I was contacted the next Tuesday (interview was on a Friday) with an offer.