Staff Engineer (Global Billing, Payments & API)

About the role

This role builds and evolves the shared API platform, integration patterns, and technical standards for Kaluza's global billing and payments engine. You will lead system design and architecture to enable consistent, scalable capabilities across multiple markets and energy retailers. The position is central to the company's transition toward a shared global core platform.

Responsibilities

• Own system design and architecture for the API Platform and Standards squad.
• Create and challenge product and engineering proposals, backing design trade-offs with data.
• Diagnose and resolve complex technical and product issues across various domains.
• Establish architectural patterns and technical standards for other teams to build upon.
• Turn ambiguous technical requirements into concrete execution plans.
• Influence engineering leadership, product, and adjacent squads to align on technical direction.
• Mentor and upskill engineers to contribute to a wider learning culture.

Required skills

• System design
• Architecture
• API design
• Technical standards
• Billing systems
• Payments
• AI
• LLMs

Nice to have

• API gateway
• API versioning
• Developer experience
• Financial services
• Multi-market platform model

Benefits

• Pension Scheme
• Discretionary Bonus Scheme
• Private Medical Insurance
• Virtual GP
• Life Assurance
• Climate Action app access
• Free Mortgage Advice
• Eye Tests
• Retail discounts
• 5% Flex Fund

About the Company

Kaluza is the Energy Intelligence Platform that orchestrates millions of real-time decisions across homes, devices, markets, and grids. They help energy companies overcome challenges and accelerate the shift to a clean, electrified future.