Tableau Data Operations and Grouping

I am looking for a Tableau expert to help me with a project that involves working with CSV files as the data source. Specifically, I need help with various data operations like summing, calculating averages, and computing percentages. Additionally, I might need to utilize different groupings for these calculations (e.g., by year, month, org code, category, etc.).

Key Requirements:
- Expertise in Tableau
- Strong understanding of data operations (e.g., sum, average, percentage calculations)
- Ability to work with CSV files

Optional, but Ideal:
- Familiarity with SQL databases
- Experience with complex data groupings in Tableau

Please note: The specifics regarding the groupings are yet to be determined, so flexibility in accommodating various groupings would be appreciated.