[ddorian43]

Crawling should be the easiest part.

[marginalia_nu]

I don't know if there is an easy part in search. Almost every aspect of it has unique challenges.

Large scale crawling is primarily a challenge in balancing the logistics in a way that is kind to both the crawler and the data consumers.

Distributed crawling, if you go that way, is also non-trivial as you're effectively juggling a shared rapidly mutating state in the dozens gigabytes.