Two of the people most responsible for Zynga’s mobile and social games over the last two years have moved on to the developer that hopes to turn into the next big thing.

Dragon Story developer Storm8 revealed today that it has hired Tim LeTourneau and Steve Parkis to take over as the company’s new chief creative officer and president of games, respectively. Both men come from similar positions at Zynga, where they oversaw the development and production of the FarmVille and Zynga Poker franchises. Storm8 already has more than 400 million active players, and it brought in LeTourneau and Parkis to help them increase that audience even further in the $21 billion mobile-gaming industry.

Both new executives have extensive history in games. Prior to Zynga, LeTourneau worked at Electronic Arts for almost two decades. Parkis spent his early career establishing game franchises for Disney.

“Since our founding nearly six years ago, our goal has been to build the largest mobile-games network by delivering the highest-quality mobile gaming experiences to players around the world,” Storm8 chief executive Perry Tam said. “The expansion of our executive team underscores our commitment to this mission and further accelerating Storm8’s trajectory. Tim’s and Steve’s combined creative and operational leadership bring us the tandem skill set required to take Storm8 to our next stage of growth.”

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The company notes that players on mobile have already downloaded Storm8’s games more than 600 million times, but Tam believes that LeTourneau and Parkis can push the company to do even better — and to make more money while doing it.

“I love creating and launching games even after 20 years in the business,” said LeTourneau. “Storm8 represents a great opportunity for me to join a leader in the mobile market with a differentiated network focus and diversified game portfolio. I am excited to leverage the Storm8 platform to build the best games that drive the largest mobile gaming network in the world.”

“I share Storm8’s spirit of fun and commitment towards making amazing gaming experiences across a broad network of users,” said Parkis. “I look forward to working with a fast-moving, mobile-first market leader and continuing to build on the cornerstones of Storm8’s success: culture, team and technology.”

This isn’t the first time Storm8 has picked up some talent that left Zynga. Earlier this year, the company picked up its chief strategy officer Terence Fung after he departed the FarmVille developer.

While Zynga was one of the companies that kicked off the social-gaming boom a few years ago, it has struggled to transition to mobile. FarmVille was a massive hit on Facebook, but it hasn’t had the same impact on smartphones and tablets. This has partially led to a lot of turnover in the executive ranks at Zynga, which studios like Storm8 are taking advantage of.