How would you manage indexation on a large e-commerce website?

Example:

Product pages → index if valid/unique
Category pages → index
Internal search → usually exclude
Tracking parameters → consolidate
Sort parameters → control
Temporary filters → control
Out-of-stock products → business-specific policy
Expired products → redirect, 404/410 or retain depending on context

The policy should be implemented consistently across templates rather than manually page by page.

Then validate:

• index coverage;
• canonical selection;
• sitemap quality;
• internal links;
• crawl distribution.