But there are "cubic bazillions" of possible URLs that are being requested. Even if they boil down to "only" some millions actual commits, their rendered HTMLs are all different.

have a hackathon to solve for this. OP says it's not a problem for him right now but if we extrapolate what he's talking about it's definitely a problem aaaaaaand It's totally solvable, Even with all of the crazy combinations he's talking about it's still solvable. And it's already been solved using patterns we see in streaming services. This is completely hackathonable. but why do we even need to bother with this? The slurpers are the cause of this, and they can cause this problem because of Murphy's Law. well you can only account for Murphy's Law with good architecture or something like that or whatever. Ha ha hackathon.

Yes, this is very difficult to solve for sites with many URL variations, like git repos and heavily threaded forums. Your cache is always full, but the hit ratio is abysmal.