Develop a Program for Data Extraction from Pdf Documents

I need a program developed that can read and extract specific data from PDF documents.
After enter a webiste with the extract data open another pdf and extract more data. The program should be able to handle standard text-based PDFs. The extracted data needs to be structured and saved in a usable format (e.g., Csv, json, or potentially inserted into a database). Please describe your experience with pdf parsing libraries and tools, and propose an approach for handling potential variations in pdf layouts or structures. The final deliverable should be a functional program with clear instructions on how to use it.