My BigCommerce store is stable and already generating sales, but it needs a visual refresh and smarter functionality to reach the next level. I want conversion-focused on every screen size. Alongside the new look, I also need full-stack support for: • Upselling and optimized checkout flows that surface add-ons, cross-sells, and post-purchase offers without slowing the site down. • Graphic assets that match the updated design (icons, banners, and any custom illustrations). • Coding the redesign directly into BigCommerce (Stencil, HTML/CSS, JavaScript) and keeping performance tight. • Ongoing long-term edits, so any future tweaks or A/B experiments are handled quickly. • Integration with third-party services—think email marketing, reviews, or shipping apps—using BigCommerce APIs or ready-made apps when they make sense. Deliverables will be considered complete once the new homepage is live, the checkout upsell logic works end-to-end, third-party integrations sync correctly, and Lighthouse scores remain in a healthy range.