[throwaway744678]

A classic way to do these redirects is on the front web server itself: .htaccess, nginx config, etc.

When you change the structure of your urls, you can generally generate redirect rules to translate old urls to the new structure. Or run a script to individually map each old url to its new one.

Note: I've never done the layter for more than a few hundreds urls, I don't know if it scales well for a very large site