'Do' and 'does' are both forms on the existing indefinite tense in the verb 'to carry out.' Which a person you can expect to use will largely depend on the sentence's matter. Their use is nearly similar, aside from 1 occasion where you can use 'do' and never 'does.' https://financefeeds.com/lightchain-ai-captures-real-momentum-while-avalanche-focuses-on-layer-1-speed-without-demand-signals/