Twilio library? That defeats the entire purpose of this, which is to allow simple CRUD operations on a JSON file to resolve against using a React/Angular style SPA. This is not intended for more complex web applications. Also, further this is simply example code, not something I am planning on updating in any way, because it served the purpose for what I needed.
I actually have made an SMS Marketing App and for that I used Python (Flask), PostgreSQL, Angular 4, and Docker with nginx to bring it all together.
I specifically say in my blog post that this isn't intended for teams or anything more complex than flat file CRUD. This would blow up really quickly and be a nightmare to work with as a team - there isn't even any sort of validation.
The truth is, most of the time I write APIs using either Java 8, Express/NodeJS in TypeScript, or Python with Flask with a persistence layer like PostgreSQL all backed by Docker. I felt like that was huge overkill for storing just the names of shows, and I didn't want to have to store this on a VPS with a reverse proxy... I figured one PHP file was really all I needed for the CRUD operations.