title: Implementation patterns for multiple programming languages in a single web application
body: <p>I've only created web application with one programming language (like python or js).</p>
  <p>I'm aware that multiple programming languages are used to create advanced services. But I don't how exactly does it works together, what are the different patterns to implement this.</p>
  <p>Here's a scenario. If we have a Nodejs application that accepts like 100s of key-value pair data ( say JSON ) from a user and if we need to work on the data using Haskell... which are compiled to binary.</p>
  <p>I have a hierarchy of data of say, a set of people and their managers along with some performance metrics and their points. And I want to pass them to a program written in Haskell to compute some values based on their role etc...</p>
  <p>What methods could be used to pass the data into the program?</p>
  <p>should I be running a server that accepts the values as JSON (via HTTP) and parses them inside Haskell?</p>
  <p>or can I link them with my nodejs application in some other way ? in that case, how can I pass the data from nodejs application to Haskell?</p>
  <p>My concern is also about the latency, It's a real-time computation that would happen every time requested.</p>
  <p>For instance, facebook uses Haskell for spam filtering and an engineer states they use c++ and Haskell in that service.. c++ accepts input passes to Haskell, which returns back with info. how might be the interfacing working here?</p>