The strongest files are built from records the company already generated in the ordinary course: internal manuals and their revision history, training curricula and attendance records, design notes, incident reports and the documents the transferee personally wrote. Declarations help, but they carry weight in proportion to the contemporaneous material behind them.
Prefer the documents that were not written for the petition
Evidence created for the purpose of a filing invites the question of whether it merely restates the legal test in the company's words. Evidence created years earlier, for the company's own reasons, is far harder to argue with. Version histories showing who revised a procedure and when, training records showing who taught whom, and internal correspondence discussing a problem and its solution all place the employee inside the company's methods rather than merely near them.
Hypothetical example: a commissioning specialist at a Sainte-Cécile-de-Milton systems firm wrote the installation and start-up manual that every one of the company's crews now follows, and the document management system records each of his revisions with a date. Attaching that history, together with the earlier manual he replaced, demonstrates authorship and development in a way that no summary written this month can match.