I am trying to develop an interactive IVR Gaming service ( calls are responded programatically with mp3 played to user, never forwarded to another phone) and I planned to just buy a phone number from Twilio and then write a script for handling the calls. What happens if let´s 100 people call the number at the same time, can the script answer to each call in parallel and let the user navigate through an IVR tree ? or am I "forced" to queue the calls one by one and then feed them to the script ?
I have read the documentation and I don´t find anywhere how a single twilio number can handle multiple inbound calls.
One number can definitely handle multiple inbound concurrent calls - whether using Studio Flow, Twilio Functions, or your own web server / api handling the Twiml.
This resource has the info: "How fast can I place or receive phone calls":
Incoming calls
Twilio places no limitations on the rate at which projects can receive inbound calls. Every incoming call received at your Twilio phone number corresponds to an HTTP request we submit to your webhook / request URL or SIP Trunk Origination URI. We recommend users make sure your server is capable of handling the load if you are expecting a large amount of concurrent inbound traffic.