Hi Luka, and welcome to the community!
Here are some answers as you vet consultants.
Send data to external system if a record is created or updated
Apply customized function to a list of records
Customized function can be integrated
I think you are describing a use case where you would extend the existing formulas in Airtable to provide your own library of formulas. For example - Airtable lacks a Split() formula and ideally, it would be nice to add one. Sadly, this is not currently possible, however, there are ways to enhance any Airtable solution using the REST API and external services that can perform computations on rows and fields.