A lot of traffic means the script or code will execute multiple times, sometimes – concurrently even! This server needs to be capable enough to handle a high amount of requests simultaneously. It should not restrict your web application from executing processes. All this can never be possible in a shared hosting environment.

If you are already familiar with the technical basics and requirements then the simple one-shot answer is – A Dedicated Server with very high capacity RAM and CPU.

Your selection should be based on the following features:

1. RAM: High capacity RAM of around 128 GB is required for at least 15000 – 25000 visitors simultaneously. If RAM consumption is very high and your RAM configuration is not very high then your site will not open fast or it might not even open!
2. CPU: 3.3 GHz with 16 cores or above is highly recommended for fast loading, hassle-free execution of process, and good user experience. If the processor will not be of at least this configuration then it will not be able to handle multiple requests. It will not execute multiple processes at the same time and hence the load of the server will increase. As soon as the load increase, the website might stop opening. The processes will stop executing and it can freeze! And in the end, you are left with your visitors saying this to you – “Website is Down!“
3. Hard Disk: This parameter is based on the size of your sum total of web pages and other files in your server. Mostly, people who do not have any sort of heavy files like video or software files, go for Hard disks of 1TB to 2 TB. But size is not so important as compared to the type of hard disk you are purchasing – SSD or HDD.
   For this type of specific requirement, you should only and only go for SSD. SSD is far better than HDD in speed.
4. Leased Line Connection: If the internet speed of your Dedicated Server will not be at least above 40Mbps.
   The topper of internet speed in the USA. The following image shows this data where the highest speed measured by pcmag.com is 67 Mbps in Kansas city. With only fast speed your server will be able to serve your files to the clients.