Online CSV Cleaning Tool

I’m putting together a small web interface where I can paste or upload raw CSV text and instantly receive a cleaned-up file in return. The sole purpose of the tool is data transformation, focused specifically on data cleaning.

What must happen each time a file is processed:
• Removing duplicates
• Formatting all date fields into a single, consistent format I can configure (e.g., YYYY-MM-DD)
• Detecting and correcting obvious data entry errors (extra delimiters, stray quotation marks, empty header names, etc.)

A simple drag-and-drop or text-area input is fine; the cleaned CSV should download automatically and, if possible, show a quick before/after preview in the browser. I don’t need user accounts or long-term storage—everything can run client-side or as a lightweight backend service (Python + Flask, Node, or anything similarly straightforward).

Please structure the code so future rules (like additional field validations) can be slotted in easily, and include a short README explaining how to deploy the tool on a standard VPS or within a Docker container.