AWS Case Study: SundayToz

Founded in 2009, SundayToz is a casual game studio that develops social games for online and mobile platforms across the globe. Its popular releases include the Anipang series, South Korean mobile puzzle games. The company offers a broad portfolio of global IP-based casual games such as Disney Pop Town and We Bare Bears The Puzzle. Anipang 4, released in June, 2020, topped the game download charts on three major application stores right after its launch.

SundayToz launched Anipang, a mobile social game serviced by Kakaotalk mobile messaging app in 2021 and saw a record-breaking success. In less than two months since its launch, the game had 10 million daily users, 1 million new daily subscribers, and 3 million concurrent logins and became a household name in South Korea. To deal with increasing hourly traffic, SundayToz needed additional servers, but it did not have extra servers reserved in its internet data center (IDC). It ordered additional servers, but the lead time was too long and there was not enough space in the IDC to install the servers. In other words, the IDC was not equipped for extremely fast growing traffic the company was experiencing therefore was not able to handle the surging traffic. 

There were other issues too. The cost of managing servers was high due to aging servers, and the failures and security issues of the old servers made it hard to provide stable services, not to mention that some of them were idle and causing management headaches. In the face of these challenges, SundayToz reviewed the benefits of the cloud – scalable infrastructure, strong security, and flexibility – and decided to move to the cloud.

SundayToz built a hybrid environment based on both the IDC and AWS Cloud and used it from 2015 to 2018. With AWS, it saved a lot of costs as it no longer needed to spend money on managing old servers. Adding, refreshing, and updating resources became much easier, and the automation of day to day management tasks saved a lot of time for the IT staff. Additionally, the flexible management of servers enabled by AWS Cloud that responds to traffic changes automatically increased efficiency in resource management and improved both security and service reliability. 

Prior to AWS, SundayToz had to install all necessary monitoring tools to every new equipment added in the IDC on its own. But with AWS, it uses native monitoring tools such as Amazon CloudWatch and automation tools such as Auto Scaling for easier and less complex monitoring. It also uses services like Amazon Kinesis and Amazon Simple Storage Service (Amazon S3) to collect logs, and Amazon EMR and Amazon Athena to collect, process, and analyze data from the collected logs. 

With the launch of Anipang 4, it implemented Amazon Elastic Kubernetes Service (Amazon EKS), an AWS managed container service. Amazon EKS enables higher stability and more efficient  operation of services as it offers continuous deployment through blue green deployment. Changmyung Lee, CTO of Sunday Toz, says “Our developers were stressed out before and after deployments. However with Amazon EKS, the pressure is long gone. We used the blue green deployment model of it to build a real-time battle system on Anipang 4, and it allowed us to easily roll back if any problem and to gradually apply updates. This reduced risks of unexpected server failures and relieved pressures off from our developers. This also helped us deliver maximum customer experience as it eliminated the need for server maintenance and shut down of the service.” 

Since 2019, SundayToz launched all of its games on AWS and completed the migration to AWS in January 2020. Lee says “We were already using a lot of cloud technologies. So we thought moving to AWS would make more sense in terms of reducing operational burdens and accelerating service operations. AWS provides scalable, stable, and secure infrastructure and holds many customer references. It had everything we needed so it was an easy choice.” 

SundayToz develops and supports over 20 games with about 80 developers, of which only 20 of them are server developers. But on AWS Cloud, SundayToz has been successful in operating its services both in Korea and across the world. 

Lee adds, “When we first introduced Amazon EKS, we had concerns — we were not sure if it would be the best choice for Anipang 4 and what we were going to do if there were any issues. AWS Account Managers and dedicated Solutions Architects supported us throughout the process from designing to testing to training and assured us that we were making the right move. When we saw how it finally turned out, we were very satisfied with the results.”

SundayToz will continue to add more global IP based casual games to its product portfolio which includes the widely known Anipang series and expand to the global market. It plans to work more closely with AWS to build a win-win relationship and launch more games to the global audience.

For more information, please visit Amazon EKS.