Data Conversions.
Over the last 30+ years I have had to convert/export data from many systems, text files into databases for example.
A very common requirement is Excel spreadsheets into databases, this can be complex depending on how the spreadsheets are constructed.
Microsoft Access into Microsoft SQL Server is a very common requirement, normally quite straight forward unless there is documents/images embedded in the database, it just requires more work if that is the case.
Recently I had to extract all the data from a Microsoft Dynamics 365 system and import it into a Microsoft SQL Server, this was a complex process but we did get all the data across.
I have had to move data from Microsoft SQL Server to MySQL, SQLite into Microsoft SQL Server is a common requirement.
Upgrades of old unsupported versions of Microsoft SQL Server like 2008 to newer/current versions of SQL Server, is a common requirement.