What the listing shows. The listing doesn't open with local experts, because too few are based in Costa Rica so far. The experts listed are located outside Costa Rica and work with Latin American merchants, which means every hire from this page is a remote one.
Panama has the same set-up. Stores in Panama get what Costa Rican stores get from Shopify: no Shopify Payments, Manual Tax only, POS hardware from outside retailers and a Spanish checkout. A small group of experts is based in Panama City, and their page is linked below. Someone who has launched a Panamanian store has already solved most of a Costa Rican one; ask whether they've priced a store in colones, then walk its checkout yourself.
The payment provider account is the one to guard. A third-party provider holds your customers' payments, so open that account in your own business's name, along with the Shopify store itself. The expert gets staff access to Shopify and, only if the integration needs it, limited access to the provider. When the project ends, you remove them; nothing has to be handed back.
Working hours decide how launch day goes. Agree a window each weekday when the expert can be reached, and how a checkout failure gets escalated outside it. An expert whose day barely overlaps yours can still do excellent build work. They just shouldn't be the only person on call when you go live.
Colones or another currency: decide before the quote. Your store sells in Costa Rican colones (CRC), while a remote expert could quote in something else. Agree the contract currency, who covers transfer fees and how exchange-rate swings are handled on longer projects, so the quote and the final invoice match.