title: How to do feature engineering of real time data?
body: <p>I have made a good linear regression model with following step:</p>
  
  <ol>
  <li>Data Integration</li>
  <li>Data normalization/scaling(data preprocessing &amp; feature engineering)</li>
  <li>Model Building(using linear regression with SGD using cross validation)</li>
  <li>Testing</li>
  </ol>
  
  <p>My question is if we use this model in production environment then how can we do feature engineering of real time data because this <strong>model is built with feature normalization and scaling</strong> so how real time data can be normalized and scaled to get a good prediction? We don't need explicit feature engineering for cross validation and testing step because this can be done in data preprocessing step before building a model. What about <strong>real time data feature engineering</strong>?</p>