contact changes monitoring

lastUpdatedDate = DateTime.UtcNow;
urlTemplate = "htts://api.wildapricot.com/v2/accounts/NNN/contacts?$async=false&$filter='Profile last updated' gt '{0}'";
while(true)
{
  // filter contacts which changed since last check
  url = string.Format(urlTemplate, lastUpdatedDate);
  
  // update last check timestamp
  lastUpdatedDate = DateTime.UtcNow;
  
  modifiedContacts = downloadFromApi(url);
  
  // notify external service
  foreach( contact in modifiedContacts )
  {
    notifyContactupdated( contact );
  }
  
  // wait 30 seconds
  wait(30000); 
}