Magento 2 Hyvä Theme Upgrade

I am moving my store from the default Luma design to the Hyvä theme and I want the switch to translate into tangible performance gains. The checkout page is the first screen that needs to go live on Hyvä, followed by the rest of the site, so that is where I’d like you to focus your energy... (Budget: $250 - $750 USD, Jobs: CSS, Git, JavaScript, Magento, Magento 2, PHP, Redis, Web Development)