Download and backup deployed SharePoint solutions from the config database. See https://jcallaghan.com/2011/09/backup-and-download-solutions-in-sharepoint-from-the-configuration-database/ for more information. #Website

Export-SPSolutions.ps1

# Download and backup deployed SharePoint solutions from the config database

Add-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue

$dir = "C:\Solutions\"
$solutions = Get-SPSolution

if(!$solutions){
  write-host "No solutions found." -foregroundcolor Red
}else{
  New-Item -ItemType directory -Path $dir -force | Out-Null
  write-host "Saving solutions to $($dir)."

  foreach($wsp in Get-SPSolution){
    $name = $wsp.SolutionFile.Name
    $wsp.SolutionFile.SaveAs("$dir\$name")
    write-host "Solution '$($name)' saved."
  }

  write-host "All solutions have been saved successfully." -foregroundcolor green
  ii $dir
}