Helen of Troy interview questions

After 2 phone interviews (1 with HR and 1 with the engineering manager) they asked me to come to New York on my own dime (always a red flag). When I arrived, I thought the offices were really nice and clean, but it had a standoffish vibe. Although they advertised for an entry level position, they wanted someone with 2-4 years of experience (I had 2 years at the time). My interviewer only set aside 15 minutes for our interview. Somehow in that 15 minutes I was told the pay was in the low 50s (this is a couple standard deviations below the mean for a degreed engineer with experience in New York). They gave me a pretty detailed assignment by email and a couple of weeks to complete it. I heard nothing from them for about 3 weeks after I submitted, and the manager finally wrote back to my emails to let me know they were no longer hiring for the position. A few lessons I've learned from this interview experience: 1. Be cautious about interviewing with companies that don't pay travel expenses. 2. Be cautious about interviewing with companies that only set aside 15 minutes for an in-person interview. 3. Do not participate in assignments that require a suspicious level of completeness. Every 4-6 months, I see the position that I applied for advertised on various job boards, which indicates that they either have a problem with turnover or a solution for getting free work done by applicants.