[throwaway427]

I've always thought some sort of straightforward partitioning strategy, even the simple one from Building Scalable Web Sites[1], or the Instagram model, would fit pretty nicely over most over multiple Reddit product dimensions -- partition by subreddit (with special instances for exceptionally busy reddits), partition by domain, etc.

[1] Hard to believe that book came out 12 years ago

edit: s/shard/partition