(Senior) Full-Stack Software Engineer - Financial Infrastructure & Payments (m/f/d)

• Architect and build billing, invoicing, and monetization systems for the global energy transition, including PSP-backed payments and reconciliation.
• Design, build, and maintain business-critical full-stack systems, from scalable backend services and APIs to user-friendly frontends for invoices, payments, and subscriptions.
• Partner with finance, operations, and product to translate billing requirements into technical solutions, ensuring compliance and audit-friendly reporting.
• Own slices of the invoice lifecycle (generation, delivery, archival), templating and localization, and reconciliation and reporting.

By building the financial infrastructure behind 1KOMMA5°'s virtual power plant, you enable the scalable transition of 1.5 million households to renewable energy, directly accelerating the fight against climate change.

• Experience writing maintainable, reusable, and testable code in TypeScript, with strong skills in both frontend frameworks and backend technologies.
• Strong understanding of API design, data modeling, and system integration (RESTful or GraphQL), including patterns for idempotent money movement and auditable billing events.
• Proven ability to own features end-to-end, from UX and architecture to deployment and monitoring.
• Excellent written and spoken English; German is a plus. Residency in Germany required.

• International, dynamic, and highly motivated team
• Direct impact on climate through accelerating the energy transition
• Work with and learn from smart colleagues
• Direct contact with core decision-makers
• Full-time position in a thriving European scaleup
• Remote work (Germany-wide) with offices in Hamburg, Berlin, or Munich
• EGYM Wellpass for health balance
• Futurebens benefits and discounts
• Job bike leasing (city bike or e-bike)

1KOMMA5° is building the energy system of the future with Heartbeat AI, integrating solar, batteries, heat pumps, and e-mobility into an intelligent virtual power plant to make renewable energy affordable and accessible, aiming to transition 1.5 million households by 2030.