Staff Engineer (Global Billing, Payments & API)

Location: London, Bristol or Edinburgh, UK (hybrid, three days a week in the office)

Kaluza runs the billing and payments engine behind some of the world's biggest energy retailers. This role builds and evolves the platform other engineering teams build on top of: the shared APIs, integration patterns, and technical standards that let billing and payments capability get built once and reused everywhere, instead of rebuilt separately for every new market or client relationship.

That matters because of where Kaluza is headed: as we grow into new markets and take on more of the world's largest energy retailers as clients, having a consistent, well-designed API platform is what lets new capability get adopted quickly and safely across every team that needs it, rather than each team solving integration and standards problems on its own. Getting this right directly shapes how fast Kaluza can extend billing and payments capability to new markets and clients.