title: Seeking advice on building web app that splits datasets
body: <p>I am looking for guidance on a project I am working on. For reference, I am skilled in HTML, CSS, and pretty familiar with JavaScript, and that's where my coding knowledge stops.
  I am attempting to create a web app the allows the following high-level workflow</p>
  
  <ol>
  <li><p>User uploads CSV file via web UI</p></li>
  <li><p>Application splits data of file randomly into two groups</p></li>
  <li><p>Application creates two CSV files, each containing one of the two
  data sets</p></li>
  <li><p>Application surfaces links via the web UI for the user to download
  each of the files</p></li>
  </ol>
  
  <p>Here is a more specific example:</p>
  
  <ol>
  <li>User uploads CSV files with the following dataset '1, 2, 3, 4, 5, 6, 7, 8, 9, 10'.</li>
  <li>Application transforms this into two equally sized random data sets such as: '2, 3, 5, 6, 9' and '1, 4, 7, 8, 10'.</li>
  <li>Application creates two files. The first containing '2, 3, 5, 6, 9' and the second containing '1, 4, 7, 8, 10'</li>
  <li>User is presented with two links, 'Dataset 1', and 'Dataset 2', which clicking either initiates a file download.</li>
  </ol>
  
  <p>I am comfortable building the front-end of this, but looking for advice on how to design the backend. Looking for the path of least resistance here and any guidance is appreciated.
  Thank you!</p>