What requirements don't you have?

When designing software, the requirements you don’t have are as important as the requirements you do. Identifying what you can compromise on — what can be slow, or stale, or inflexible — is usually the key to an elegant design. Elegant systems drop some requirements For instance, take preforking web servers like Unicorn. Because they lack the feature of shared mutable state between server instances, they can run each server in its own process, which provides isolation for free. Because Unicorn specifically ignores the problem of slow client handling1, it can queue requests directly on Unix sockets, drastically simplifying the implementation. Because S3 does not support atomic multi-key updates — you cannot update multiple blobs in a single transaction — it can store data at the blob level however it chooses. That makes it much faster, since reads and writes don’t have to cross storage partitions, and much easier to scale, since less coordination means fewer sources of truth. StatsD…