While Zynga’s games may look simplistic, there’s a lot of power and technology behind their games.

Zynga detailed the evolution of their zCloud servers that host all of their games yesterday. It’s a fascinating look at the technology behind the social games that everybody knows and loves (or hates).

The company hosted its games on third-party servers at the start of their business. They didn’t expect any of their games to take off as fast as Farmville did. They say that within the first six weeks on Facebook, Farmville grew from zero to 10 million daily active users. The game hit an astonishing 25 million DUAs within the first five months.

They moved Farmville to Amazon’s cloud servers. They then realized that the cloud was the future of their business. The only problem is that they were on the public cloud. While it allows for massive expansion, it doesn’t allow the developer to optimize how the server handles each game.

After realizing this, the company started work on their own private cloud infrastructure called zCloud:

As infrastructure that is private to Zynga, zCloud physically resides in our own datacenters and is designed specifically for social games in terms of availability, network connectivity, server processing power and storage throughput.

It doesn’t mean that they stopped using Amazon’s service, however, as they used both cloud networks to host their games that now had millions of players. They used a new method of cloud computing in that they would use public cloud servers for the initial launch and explosion of players and then slowly move everybody over to their private cloud network.

They are slowly moving all of their games over to their private datacenters now. They even began to launch games in zCloud instead of public servers. At the start of last year, only 20 percent of their DAUs were in the zCloud. At the beginning of this year, 80 percent are now in the zCloud.

What they call a “new hybrid cloud” could be the future for large companies like Zynga that rely on massive amounts of data to support their products. Leveraging the abilities of private datacenters with what public cloud servers can supply could really speed up all kinds of applications from games to streaming films or music.

As a final note, here’s some mind-blowing facts about Zynga’s zCloud:

[Infographic courtesy of Zynga]