AWS is clearly gearing up to make S3 Express a potential alternative to EBS disks. Like EBS, S3 Express is single zone. Earlier this year, AWS added the conditional write primitive to both S3 and S3 Express. Now it has released the ability to append to objects in S3 Express.While append seems like another milestone towards disk-like behavior at first glance, a closer look reveals a more nuanced reality. To understand, let's look at the problems faced by S3-based distributed systems and how they...