Being a small startup (?), are you sure you have the capability to sponsor visa?
I'm also concerned by the fact you're looking for someone to work on NLP/deep learning stuff, which forms the core offering of your company, but that person will be an engineer rather than standing on equal footing as a co-founder.
I'm also concerned by the fact you're looking for someone to work on NLP/deep learning stuff, which forms the core offering of your company, but that person will be an engineer rather than standing on equal footing as a co-founder.