SRE here, some load balancers do support weighting. However, most of time since we are using cloud machines or hardware refreshes are mostly in large cycles, th

SRE here, some load balancers do support weighting. However, most of time since we are using cloud machines or hardware refreshes are mostly in large cycles, the fleets running X service is the same and therefore standard round robin works well enough. It appears that Dropbox does not do that and therefore, they needed a solution like they built. One of those, "At your scale, this makes sense. Few companies are at this scale." EDIT: It probably wouldn't be hard to home roll something like using HAProxy/Caddy APIs and Prometheus.