About the Role Join the core infrastructure team at an early-stage energy technology company, building the backend systems behind dynamic electricity plans and reliable billing. You will help develop scalable services for billing and energy-market communication. What You'll Do • Design backend systems that reduce complexity in billing and energy-market workflows. • Scale core infrastructure to support growing transaction volumes and market demands. • Ship features and improvements through rapid iteration and practical engineering decisions. • Raise technical standards through code reviews, architecture decisions, and mentorship. What We're Looking For • At least 3 years of hands-on experience building and shipping reliable backend systems in production. • Strong TypeScript and Node.js skills, including asynchronous programming. • Experience with PostgreSQL and ORM-based data access, such as Drizzle or similar tools. • Experience building Next.js backend services, including API routes or server components. • Familiarity with distributed systems and designing scalable, maintainable services. • Experience integrating Stripe payments and billing workflows. • Strong computer science fundamentals through formal education or equivalent practical experience. • Fluent or native-level German proficiency, C1 or higher. • Interest in early-stage environments, an ownership mindset, and evidence of strong technical ability through projects, research, competition, or founding work. • Broad application-building experience and clear written and verbal communication skills. Compensation & Benefits Annual salary of €80,000 to €120,000. Visa sponsorship is available. Location On-site in Berlin, Germany, five days per week.