congstar Cloud

For the development of the platform, congstar has enlisted support from two long-standing partners: AOE GmbH from Wiesbaden and the previous software operator, Deutsche Telekom MMS GmbH, like congstar, a subsidiary of Deutsche Telekom. congstar and AOE have had a successful strategic partnership on equal terms since 2008. Together, both companies shape digital processes for the telecommunications industry and have grown together technically and culturally. The focus of the collaboration is always on the satisfaction of congstar's customers (congstar has been voted as the top mobile provider twelve times in a row by readers of the magazine "connect," and Focus Money awarded congstar the title of "Fairest Mobile Provider" from 2012 to 2023). The goal is to always align solutions, products, and features  with the needs of the users.

In addition to the collaborative partnership and AOE's familiarity with the specific circumstances of congstar, AOE's demonstrated ten years of expertise in the field of public cloud solutions was a decisive factor for the commissioning. Furthermore, congstar is currently actively promoting its internal DevOps culture, which brings developers and users closer together. The business is involved in the development process, making it easier to anticipate customer needs. AOE has also been highly positioned in the DevOps field for almost 15 years and supports its customers in delivering applications and services faster and of higher quality than would be possible with a conventional software development model.

Traditional hosting infrastructures are often difficult to update and have limited capacities. Consequently, they were no longer a viable option for congstar's development teams, who desired a modernization of both infrastructure and development methods and practices.

The existing separation between software development (Development) and operations (Operations) also led to opacity and cumbersome organizational coordination between the respective departments. Developers knew little about how the software they developed actually operated in practice, while the operations team rarely engaged with the development process. Additionally, due to the classical hosting structure, the developers' request for a service mesh – a dedicated infrastructure layer that controls service-to-service communication across a network – could not be fulfilled.

Initial cautious steps towards cloudification, initially under the radar and only with non-critical, team-internal services, were then undertaken by the development teams themselves. After these testing phases proceeded very well, the official launch of the "Cloudification" project at congstar took place. Migration to the AWS-Cloud became part of the company's strategy, and the project quickly gained momentum. congstar emphasized supporting cloud migration from the outset with sustainable management attention and preparing employees at all levels, from decision-makers to developers and IT teams, for the changes and imparting the necessary skills and knowledge to effectively manage the cloud infrastructure and services.

In the first step, the general cloud strategy was planned. Then, nearly twelve months were needed for the actual platform build. Among other things, the project team designed and implemented a container infrastructure with Kubernetes as the orchestration solution and a highly available, multi-cluster Kubernetes platform in the AWS-Cloud. Additionally, autoscaling, a method in the cloud computing environment that automatically scales the number of servers within a server farm, and an artifact management solution to manage DevOps artifacts in the cloud were also implemented. An application container technology was also introduced to support congstar in modernizing legacy applications in the future.

In phase two, the migration process began gradually. The migration process was set up for a large number of microservices. Initially, the migration of microservices with little business value and no dependencies was prioritized for testing purposes to minimize risks. After this process went smoothly, the team proceeded with migrating centrally operated microservices. To maximize security in the cloud, the DevOps team led by AOE introduced vulnerability scanning. This allows for the assessment and monitoring of cloud instances, eliminating new, unpatched security vulnerabilities and open ports.

Additionally, congstar also adopts the Zero-Trust model. With this model, it is no longer assumed that everything within the network is in a secure area. Instead, every user, device, and application is considered a potential threat. Therefore, authentication is required each time to access resources. Zero-Trust provides congstar with an evolution of its security strategy, covering all aspects of cloud security.

The establishment of DevOps practices contributes to increased satisfaction among development teams. Agile working methods, which improve collaboration between developers and IT infrastructure to increase the delivery speed of software products and simultaneously accelerate bug fixing, have proven successful at AOE as part of the company culture. AOE shares this extensive knowledge and long-standing experience in cooperation with congstar. Another bonus for developers: To enhance reliability, network tasks at congstar will now be executed by a service mesh, allowing developers to focus more on their essential business logic. Contemporary infrastructure and modern working methods have a positive impact on congstar's time-to-market. Campaigns go online faster, newly developed components are deployed more swiftly, often within a single workday.

congstar is leveraging a comprehensive cloud strategy to digitize even faster and more efficiently. Thanks to the cloud, new microservices can be deployed and scaled more easily. This allows the mobile and DSL provider to bring its products and services to market more quickly and gain a competitive advantage.

The increased flexibility and scalability resulting from cloud migration enable congstar to adapt developer resources flexibly to actual requirements. Changes in the market or within the company can be responded to more quickly, and the IT infrastructure can be adjusted seamlessly. Additionally, the company has seen an increase in satisfaction among its development teams. This is largely attributed to the modern infrastructure of the cloud and the adoption of DevOps practices. Fifteen years ago, congstar embarked on the journey towards agility and drove the agenda of digitalization together with AOE. Both have now reached a new milestone in their partnership with the successful cloud migration. One of the most critical keys to the project's success remains unchanged: AOE considers congstar not just as a client but as an active member of its own team.

Migration of centrally operated microservices to the cloud

Cloud migration positively impacts scalability and flexibility

Establishment of DevOps practices

Reduction of time-to-market for new software components & campaigns

Increase in satisfaction and productivity of developer resources

Advancement of the security framework through a strategic "Zero Trust" architecture approach