Shopify Store Functionality Enhancements

I need an experienced Shopify developer to upgrade two critical areas of my store: the checkout flow and the way shoppers filter products. For the checkout, I’m aiming for a faster, friction-free path from cart to confirmation. Please streamline the existing steps, remove unnecessary page loads, and make sure every element— from discount codes to shipping rate calculations—responds instantly. Mobile performance is especially important. On the catalog side, I want intuitive filtering that lets customers narrow items by size, color, price range, and any other tags we set. The controls should appear seamlessly on both desktop and mobile, update results without a full page refresh, and stay compatible with my current theme settings. Deliverables – kept concise: • Re-engineered checkout that passes Shopify’s built-in test orders and supports all current payment methods • Dynamic product filter sidebar or drawer, fully styled to match the theme, with easy tag/collection management in the admin panel • Clean, well-commented code or app setup so future tweaks are straightforward If there’s a more efficient way to reach these goals—custom scripts, theme edits, or lightweight apps—I’m open to your recommendation. Let me know your estimated timeline and any similar Shopify builds you’ve completed.