He was 10 minutes late. This gave me quite a first impression. The interview was over an hour, and he mostly talked about himself and his company. That's totally fine and normal, but it felt more like an ego-boosting session for the owner and his company rather than an interview.

A 40min to an hour long chat with questions about your 3 biggest weakness and strength. The owner will ask if you love coffee. If you're not a coffee drinker, that will be problem.