I gave mine Purina Pro Plan for large breed puppies. I was in a similar boat, questioning what was a good choice, but my vet indicated he approved, so I stuck with it.
He’s 1.5 years old now and I give him the same thing for adults, mixed with a bit of the same type of wet food.
I purchased that ^
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I went from this https://www.chewy.com/blue-buffalo-wilderness-large-breed/dp/49683 to this ->