I applied for a position online back in August 2018, but apparently, they already filled it. About 6 weeks later, I got a call from a recruiter asking me if I was still interested. From there:
1. Standard HR/recruiter phone screen. A lot of "Are you OK with..." questions: lifting 50 lbs, getting a Class B CDL (I actually already had one when I applied), working with hazardous waste (I worked with lots of hazmat at the job I had at the time), long hours (45-55 is what they told me), working in hospitals (to screen out people with fear of needles or infectious disease). Also I got asked standard questions about my basic qualifications and job history. This was about 20-30 minutes. Also, the recruiter was very helpful!
2. I was going to relocate for the job (I wanted to move out of my current city) so recruiter set up a phone interview with the hiring manager about one week later.
3. Branch Manager (one level above the hiring manager) called me since the hiring manger was sick. Questions were initially chemistry questions (pH of HCl, isopropanol, what is a flash point) and then going into experience and scenario questions (describe a difficult situation and how you handled it, describe a time when you had to bend the rules, describe a time you dealt with a difficult customer service situation, etc). I felt some of my answers weren't the best, but I think many of the questions were intended to be tricky and awkward to answer. The interview was about 1 hour.
4. The Branch Manager seemed happy enough with me so the hiring manager set up a follow-up phone interview about 3 business days later.
5. The final phone interview with the hiring manger was quite short, 15-20 minutes. He just asked a few questions that didn't get covered already. None of them were particularly difficult. I got the impression that they were planning on hiring me if I didn't raise any red flags in the final interview.
6. The hiring manager said I would hear back from them early the following week (the final interview was on a Wednesday). The following Monday, I got an offer. I attempted to negotiate the pay up. They declined, but it was still a good enough offer to accept so I did.