Type of conjunction is used in the sentence you arrived early yet could not find a seat?

The conjunction used in the sentence "You arrived early yet could not find a seat" is coordinating conjunction.

Specifically, it's the coordinating conjunction "yet". Coordinating conjunctions connect words, phrases, or clauses of equal grammatical rank. In this case, "yet" connects the two independent clauses "You arrived early" and "could not find a seat".