Mass update 40 000 contacts information

Mass update 40 000 contacts information

Hi,

I wants to update couple custom fields (including multi-select) 40,000 contacts in crm monthly. 

I need to:
  • Export CRM Contacts in a spreadsheet
  • Modify my data
  • Put the new values in CRM
I successed doing it with a creator app but it's not working with more than 2-3,000 records.

Anybody have a reliable solution ?

Thanks,

Pascal Veilleux