Rails or Node.js for backend (RESTful API)?

Question

JavaScript

Comrades, help with the choice of technology for the implementation of the RESTful API. There will be no supercomputing on the backend, but there will be a large flow of transactions / requests (payment service). Initially I wanted to make it on Rails, in its arsenal there are a lot of gems, jbuilder, "rails is the best API service provider". But I don’t have the opportunity to work full-time on the project and we hired a programmer who advocates the use of Node.js (he also knows how to use Rails), justifying this by saying that “rails are slow, unsafe, but the node is fast and cool” (I, of course, I exaggerate, but nevertheless). If the choice remains with the node, then I will not be able to participate directly in writing the code. Therefore, it is necessary to clearly justify the choice of a particular technology. I heard companies like Airbnb and Github take the following approach: "That way Rails will serve the REST API's,
Regarding Rails speed: here is the closest case in which the developer talks about 500k requests per minute on Ruby.
In general, if one of you knows the latest Rails 5.x, Node.js and can help with good advice, justify the choice of one of these technologies, then I will be glad to hear your suggestions.

Answer 1

RoR or node.js for payment service? Seriously?
For a payment service, the following is important:
- fault tolerance (stability)
- 0% downtime
- hot code reload
- speed of work
I would take OTP + Elixir + PhoenixFramework + JSONAPI

Answer 2

500k requests per minute is very little
1000000 connections per second on node.js
1000000 connections per second on python
But in general it all depends on the load. If you have 10 requests per minute, then anything will pull. If it's completely hard, then write in Crystal or Elixir if you know Ruby