When describing my work, I often summarize it as:

Simplifying complexity to facilitate Customer & Co-worker centric decision-making.

A more elaborate version would be:

Analyzing complex scenarios through design activities that focus on listening to customers, employees and stakeholders. The aim is to create a holistic understanding of the interactions people have with a brand, its services and the organization behind them.

These insights are translated into visual and actionable outcomes that help cross-functional teams make better decisions and, ultimately, deliver better service experiences.

If you prefer the common buzzwords, I would divide my expertise into:

Experience Strategy | Service Design & Journey Management | Product Discovery | Design Research | UX Design