I wrote my own CMS with PHP & MySQL in 2005.
I got hired to the X-Cart company in 2006.
I closed 4000 hours in 2 years in Qualiteam (X-Cart company) in 2006-2008.
I left company and started freelance.
I launched X-Cart modules site, but Qualiteam banned it because of copyrights.
Next I wrote my own CMS.
Now it's named as SPA-Cart.com
I scanned it with Acunetix. It was approved on CodeCanyon. I scanned it recently with AI security scanner.
There is no "high" level security issues. My demo has a very good score on PageInsights
https://pagespeed.web.dev/analysis/https-demo-spa-cart-com/rwp4kxf8b6?form_factor=desktop&hl=en