Should i send a thank you letter after an interview?

Hi! I have interview quite a few people. I think the ones that stand out are the people that make an extra effort. So, in answer to your question, yes, I think it would be nice to send a thank you letter. It should be sent today, rather formal sounding, and you can send it to the trainer (I would think that is the actual person that will hire you). I would just quickly reiterate your experience and how much you appreciated meeting them and look forward to talking to them again soon. Short and simple. And make sure you give details on how to reach you again. Good luck!