Python Software Engineer

At PKO Bank Polski, I worked as a Python Software Engineer on projects related to PSD2 – the EU directive on payment services that introduced open banking across Europe.

My work focused on the implementation of XS2A (Access to Account) functionality in the IKO Mobile App, enabling customers to connect accounts from other banks and view them in a single interface. This feature offered real multi-bank account visibility within one app, enhancing customer experience and personal finance control.

Beyond convenience, this integration also served internal purposes: by allowing the bank to read and analyze external transaction data (with user consent), it could improve internal credit scoring models and inform better lending decisions.

The project required cross-disciplinary work that extended far beyond application logic. I was involved in analyzing both technical and legal requirements, designing middleware components, and working closely with internal teams, external vendors, and national institutions including the Polish clearing house (KIR) and other major banks.

It also involved low-level certificate handling (eIDAS/QWAC), secure interbank communication, endpoint validation, and cooperation with legal and compliance teams to ensure regulatory alignment.

This was a highly collaborative effort, combining security, legal compliance, architecture, and interoperability to bring new financial possibilities to end users within a regulated ecosystem.

Tech stack: Python, Enterprise Architect, eIDAS/QWAC, XS2A, PSD2, OAuth2, REST APIs