How do I go about building a backend for my Arduino device? I am new to Arduino, but I am putting together a project in which the Arduino Uno has multiple sensors (temperature, humidity, etc) collecting data. Right now all it is currently going to do is get the data and send it over to https://plot.ly/ to save and view the data.

Using this: http://tronixstuff.com/2014/01/21/online-data-analysis-arduino-plotly/

What I want to do is build a backend application that will instead receive this data and actually do something with it. It would use users, and all the usual backend functionality. So either some good PaaS that someone can recommend, and/or resources of what to use to build out an API that can "talk" to an Arduino. Perhaps Python or Node (NO PHP), and it should do it via Wifi to connect to the internet. 

Thank you
I use emoncms for much of my data processing along with node-red and MQTT all running on a RaspberryPi see Emoncms to get started