[mmooss]

What works best in those situations, in your experience?

Do you recreate a spreadsheet, use an existing online service, and/or create a database with proper logic, etc.? If the latter, how do users handle the UI change, and can they have an ease of creation similar to what Excel provides?

[midoBB]

In my experience it's mostly about understanding business requirements of people using said excel sheets and then replicating it to CRUD WebApps while keeping capabilities of importing said sheets and exporting them so user flows are unharmed till a wholesale transition is mandated.

Good source of money for contractors as OP said.