Ask HN: Two-week contract to hire. Is this normal?

So I had an interview last week and I think it went well. No coding questions, but lots of questions about the technology (I read about it ahead of time) and the interviewer decided to offer me 2 weeks of paid work and then they would make a decision. This is for an early employee at a startup.

I'm thinking of taking it but I'm wondering if there are any tricks I should be aware of?