Motiliti interview questions

Responded to job listing on Craigslist. Had a cordial phone screen that day, and a successful in-person interview two days later. In the evening after the interview, the company left a voicemail saying "congrats, we'd like you to join our team. Can you start Monday?" No background check, no reference check. I emailed "thanks for the invite, can you please send me a job offer in writing?" The next day they responded saying "we'll have an employment agreement in a few days, meanwhile the offer is $15/hour to start, with two weeks vacation/personal/sick time annually, and $150/month insurance benefit. After 3 months it will increase to $16/hour upon review. There is a 30 day trial period at the outset." I replied asking if they could go higher on salary and benefits. They wrote back "No. We cannot. I don’t believe this is gonna work out at this point in time." Two red flags here. First: this company wants to hire skilled professionals at fast-food wages. Second: refusing to put the job offer in writing is very sketchy. Not for me, thanks.