The document summarizes the implementation of an open source search solution for a company with over 12 million documents. It discusses three plans for implementing access control to filter search results based on user permissions: 1) storing permissions with each document and filtering at search time, 2) checking permissions directly from the file server at search time, and 3) iterating user permissions at index time and storing readable documents as search terms to filter as booleans at search time. The third plan provided fast access control while only causing up to one day of indexing lag.