If you are building a tool to help users check if their information is part of this specific dataset (similar to services like Have I Been Pwned ), 1. Data Processing Pipeline

Dealing with "Private txt" files often involves sensitive info.

: A single search bar for users to enter a "lookup key" (e.g., email or username).

What (Node.js, Python, etc.) are you planning to use? Is the goal to view the data or just verify its contents?