Ezoic
Essentially, 'load balancing' is a process that shares - or distributes - workload for servers. Overall, it strives to minimize load times by dynamically making the best use of available resources.
Ezoic uses AWS Cloud Computing, and has ten primary data centers. These are accompanied by numerous smaller distribution centers around the globe, and will always serve content from the fastest possible server for each individual site reader.
The system scales up as needed and can open up new data centers in necessary geolocations at short notice. The system is also load balanced across 100 fully redundant servers.
Ezoic's infrastructure is some of the most robust out there. The system handles over 1.3 billion pageviews per month, with 99.99% uptime. It also provides an additional layer of failover systems to help sites stay up and running even when they might otherwise go down.
As an example of robustness of the system - in the DYN cyberattack of 2016 (described as the 'largest of its kind in history') many major ISPs went down - but not a single visit going via Ezoic's servers was affected.