sccache is pretty easy to set up and you can back it with S3, memcache, redis, etc.
Same with BuildCache, except you also get a fast local cache so you effectively have an L1 and an L2 cache.
In fact, since you also have super fast "direct mode" caching that bypasses the preprocessor (like ccache but unlike sccache), BuildCache really has three logical levels of cache: direct, preprocessor and remote (S3, redis, ...).