How much requests can a dotplant2 cms application handle?

I will make some small alterations to current repo of dotplant2 ( a cms in Yii2) I am making a marketplace like amazon with this.

I hope to have almost 500 vendors registered with me who will upload their products may be 20 products everyday.

then I hope to have around 5000 concurrent users who shall be browsing my site simultaneously.

Hope the scenario is very clear. Experts, If you have played with Dotplant2 or reviewed it’s code structure/quality,

can you give me a fair idea when shall I need to upgrade to something like Java based MVC framework / or a much larger tech stack?

having load balancers, nginx, etc, having thrown in even 32-GB ram and 8 cores of cpu on AWS, can I hope that I can continue with dotplant2 without any rewrite till my site gets 20000 users browsing it concurrently.

Depends on your server, your users and the custom code you’ve introduced. 20000 users may produce different server load depending on how often user clicks something and how much is served in how many requests.

I’d get something like “ab” or “siege” and actually test it.