What programming language was used to make WhatsApp?

Whatsapp application is built on the programming language Erlang with Xampp Technology.

Erlang is a general purpose programming language and runtime system. It supports distributed, fault-tolerant, soft real-time, highly available, non-stop applications. It supports hot swapping so code can be changed without stopping a system. It was initially created to be used in several large telecommunication systems.

Erlang provides language-level features for creating and managing processes with the aim of simplifying concurrent programming. In spite of the fact that all simultaneousness is express in Erlang, processes communicate using message passing instead of shared variables, which removes the requirements for explicit locks (a locking scheme is still used internally by the VM).

It is extremely essential to pick a right programming language as well as mobile app developer for build-up your app, your programming language should supplement the core functionality of your app. Whatsapp could have utilized java, php, ruby on rails, nodejs or any of the well-known language for building their application yet they picked Erlang because that is the thing that compliments the application's features.

Whatsapp have an around 900 million active users for every month and it handles around 10 billion messages every day. That is a high simultaneousness rate on the whatsapp server, and the server handles them seamlessly without ever crashing.