I am creating e-commerce website using wordpress for my client. But I am facing very big issue . Website is very slow from backend side , it takes long time to update or load something . If I switch from one page to another page in backed it takes long time 5 to 10 secong something . I tried all solutions like memory limit 512mb , litespreed cache plugin, removed heavy and unnecessary plugins and pages . All versions like php wordpress are letest however I unable to find solution . This issue taking long time dead line is comming . Now what can I do ?