OpenCart Lightning uses whole stack of techniques to optimize and speed-up the store:
1. Critical pages (home, categories and brands) are cached and served from cache.
Cached pages are used even when customers logs in or adds products to the cart
2. One cache page is used to serve different currencies.
3. Server pregenerates next pages cache at background when page is opened.
4. AJAX requests are cached too, helping much different extensions like filters
5. Slow MySQL queries are cached for 24 hours (with the respect to data update).
6. Most OpenCart narrow places are optimized to work fast with large number of products.
7. Several vital database indexes are added and some heavy queries are optimized on-fly.