EXCLUSIVE – SaaS banking engine, Mambu announced its first major step into the retail banking space through its collaboration with German mobile bank N26.

On Thursday, Mambu announced that N26 is using Mambu to migrate all of its customers over to the bank.

The move serves Mambu’s growth strategy, not only because N26 is one its fastest growing clients in terms of customer volume, but also because it brings the SaaS banking engine into the retail banking sector, Eugene Danilkis, Mambu Co-founder and CEO told Bank Innovation.

“Given that most of our partners are mainly in the lending space, our working with N26 is a milestone for the company,” Danilkis said. “We currently work with Oak North Bank (a U.K. based lending bank), but they are slightly different because they only provide deposit products, N26 is the first bank we’re working with that offers debit cards. It’s a natural part of our evolution, and we hope to continue to build our presence in this space.”

Mambu has been working with N26 to implement its technology since N26 was granted a full banking license last year by the European Central Bank. Indeed, the mobile bank has grown significantly since, reaching the 500,000 customer mark just two weeks ago.

Another important aspect of the partnership that is exciting to Danilkis is that both entities are cloud based and working predominantly with APIs.

As a result of working with a client like N26, Mambu enhanced its account and overdraft functionalities to support the bank’s transactional needs, according to Thursday’s announcement. Mambu’s core banking system supports current accounts, overdraft and loan products at N26.

Launched in 2011, Mambu powers over 5000 loan and deposit products, serving more than four million customers across 45 countries. N26, formerly known as Number 26, was founded in 2013 by Valentin Stalf and Maximilian Tayenthal. Within 18 months of its founding, it was granted a banking license. It now operates in more than two dozen European countries.