What internal tools do you need but can't/won't buy of the shelf?

What are the type of internal tools/back office type of software that you need but can't buy for whatever reason (doesn't exist/too expensive/too complicated/hard to integrate)?

I am not talking about accounting/sales/marketing types of tools but rather software that would need to tightly integrate with the database of your core product/service and perform some actions there, or track some metrics/events, display them in a dashboard?

Looking to see if there is a pattern here then build a couple of templates/starters for those scenarios.