In order to achieve our objective and successfully launch the app, we had to overcome the following challenges: 

• Ensuring a secure environment for users to interact with sensitive data and money transfer

• Following security standards and implementing SSDLC

• Utilizing biometric single-sign-on, while keeping user interaction simple

• Creating an intuitive user interface for the end-users by porting already existing iOS UI to accommodate Google's Material guidelines

• Designing an easily maintainable and scalable architecture

• Supporting core banking functionalities and different payment types 

• Implementing features for deposits and ATMs, with a map location overview

• Including statistics, spending overview, and monthly reports for trouble-free spending tracking

• Implementing carbon footprint statistics so the users can track their carbon emission

• Enabling physical and digital card usage e.g. activating, freezing, etc.

• Allowing gift card sending and receiving with a glanceable overview of available gift cards

• Adding detailed transaction overview 

• A lot of third-party services integration 

• Focusing on app stability and scalability

• Communicating among various teams in 6 different time zones 

• Efficient planning while taking into account potential vulnerabilities and risks that may be exploited by end-users