The 67-year-old German bank accelerated its modernisation journey by migrating its core banking operations to Mambu, creating a more agile, efficient, and future-ready operating model.
OYAK ANKER Bank GmbH
OYAK ANKER Bank GmbH is a German commercial bank based in Frankfurt, with a strong presence in retail and corporate banking. Founded in 1958 as Allgemeine Teilzahlungsbank (ATB) and later rebranded in 1996 after being acquired by the Turkish pension fund OYAK, the bank now operates exclusively in the digital space, with no physical branches.
The bank offers a range of products, including savings accounts, fixed-term deposits, personal loans, and specialised services like trade finance, corporate banking, and treasury management, focusing particularly on cross-border financing between Europe and Turkey.
With total assets of approximately €1.75 billion, OYAK ANKER Bank is supported by the extensive network and financial backing of OYAK, one of Turkey's largest conglomerates.
As a long-established bank with decades of history, OYAK ANKER Bank had reached the limits of its existing core banking system.
The core had become rigid, slow to adapt, and costly to maintain, making it increasingly difficult to keep pace with the evolving customer expectations, regulatory requirements, and a rapidly changing baking landscape.
The bank recognised that moving from its ageing core with another conventional, monolithic banking platform would simply exchange on limitation for another. Instead, it sought a modern cloud-native core banking solution that would accelerate product development, streamline customer interactions, and provide the flexibility, scalability, and speed needed for future growth.
– Dr Süleyman Erol, Managing Director, at OYAK ANKER Bank
OYAK ANKER Bank’s decision to migrate to Mambu’s core banking platform was driven by their need for a modern, flexible core banking system capable of supporting their broader digital transformation.
The key appeal of Mambu’s API-first design allowed the bank to build a flexible ecosystem around the core banking engine, enabling integration with best-in-class third-party solutions and facilitating the creation of new business offerings. Mambu’s platform not only met the bank’s operational needs but also gave them the freedom to innovate and scale rapidly.
Over two and half years, OYAK ANKER Bank delivered a large-scale modernisation programme that extended well beyond core replacement, encompassing cloud migration, digital channel transformation, modern data architecture, and the integration of business-critical capabilities across the bank.
The bank adopted an agile methodology, rolling out the transformation in several phases to ensure smooth integration and minimal disruption to ongoing operations.
The success of the modernisation extended well beyond replacing a core banking system. With Mambu as the foundation of its new banking architecture, OYAK ANKER Bank transformed its entire operating model, modernising core banking, cloud infrastructure, digital channels, and data capabilities to create a more flexible, scalable, and future-ready banking platform. Delivering a programme of this scale required close coordination across technology, operations, and business teams.
The programme was delivered through an agile, phased approach, beginning with retail products before expanding to payments, treasury, and corporate banking services. Throughout the programme, Mambu's API-first architecture enabled the bank to progressively integrate business-critical systems and validate each stage before the final migration.
To minimise migration risk ahead of the final big-bang cutover, OYAK ANKER Bank carried out extensive testing and a full parallel run, validating data accuracy, business processes, integrations, and operational readiness.
This preparation enabled the bank to execute a single cutover, transitioning to Mambu without disruption to customer-facing or internal operations. The final cutover retired the bank's previous core banking system, online banking platform, enterprise data warehouse, and supporting legacy infrastructure in a single migration, completing the transition to a fully cloud-native operating model.
As with any enterprise-wide banking transformation, the implementation involved complex work spanning legacy data cleansing, migration readiness, multiple integrations, regulatory and operational resilience requirements, and managing large-scale organisational change while maintaining business continuity.
By combining disciplined programme delivery with Mambu's flexible architecture, OYAK ANKER Bank successfully completed the migration with zero downtime, providing customers and employees with a seamless transition to the new platform.
“With Mambu as the foundation, core modernisation became a structured and achievable transformation for us, driven by clear priorities, disciplined execution, and a shared vision for the bank’s future.”
- Duygu Apaydın, Chief Technology Officer at OYAK ANKER Bank
Mambu's open API architecture was central to this approach, allowing OYAK ANKER Bank to integrate regulatory reporting, treasury management, mobile banking, and other business-critical capabilities into a composable ecosystem.
Rather than replacing one monolithic platform with another, the bank built a modern architecture that could evolve as business needs changed.
Innovance served as as a key technology and transformation partner throughout the programme, helping design, develop and deliver OYAK ANKER Bank's cloud-native banking ecosystem. Beyond solution integration, Innovance played a central role in developing critical banking capabilities, orchestrating complex integrations, and modernising the bank's technology landscape on Microsoft Azure.
OYAK ANKER Bank’s migration to Mambu’s true SaaS core banking platform has already delivered significant strategic value and operational improvements. The transformation was completed with 100% uptime, enabling the bank to modernise its core banking operations without disrupting day-to-day business and customer services.
The shift to a more agile, cloud-native infrastructure has allowed OYAK ANKER Bank to reduce the time-to-market for new products by 80%, enabling the bank to innovate and respond to market demands faster than before. At the same time, the modernised operating model has helped automate 50% of manual operations, improving efficiency and allowing teams to focus on higher-value activities.
With all core operations now fully migrated to the cloud, the bank has improved its ability to respond to customer needs and adapt to the rapidly evolving digital landscape.
With the new architecture built around Mambu and the bank’s own cloud-native environment, OYAK ANKER Bank has significantly improved its capacity to connect with the broader financial ecosystem.
What used to take weeks or months in the old system, often involving rigid processes and vendor dependencies, can now be done in days, with far more control and transparency.
The successful transformation created the foundation for the next stage of OYAK ANKER Bank’s modernisation journey.
Building on the core migration, the bank continued its partnership with Mambu by adopting Mambu Payments, with implementation starting in Spring 2026. Once implemented, the solution will further support its broader strategy of building a unified, cloud-native banking ecosystem.
“This transformation marks a significant step in the continued modernisation of OYAK ANKER Bank. By moving our core banking operations to Mambu, we have created a stronger, more flexible and resilient foundation for the bank, one that enables us to serve our customers better, respond faster to market change, and support our long-term growth ambitions.”
- Ümit Yaman, Managing Director at OYAK ANKER Bank
See how Mambu’s cloud-native core banking platform can help you scale fast, integrate seamlessly, and innovate without limits.
