We co-founded and led Viafintech (Barzahlen) to 100+ FTE, one of the most successful German fintechs, active in 17 markets across the EU and USA, and sold it in 2021 for a € three-digit million amount to NYSE-listed Paysafe Group. This time we’re building a global champion for prepaid products: gift cards (Apple, Amazon, Google), airtime and eCash all in one simple API. Instead of 5 players in the chain (brand → issuing tech provider → global distributor → local distributor → client), we connect brands directly with clients via the finperks platform. Today 95% of prepaid is still sold in the Global North; we believe that for the gig economy to monetize the Global South, prepaid will be key - from Netflix and Google to Apple and Uber. Kind humans. Help build the global champion for prepaid. Tasks As a Software Engineer, you'll build the core platform that connects global brands with clients across multiple markets. Design and implement RESTful APIs that handle gift card distribution, transaction processing, and inventory management at scale Build robust, maintainable backend systems that power our prepaid product platform - from brand integrations to client-facing services Work with PostgreSQL to design efficient schemas, optimize queries, and ensure data integrity for financial transactions I ntegrate with local/global brand partners (Rewe, Amazon, Zalando, etc.) and payment providers through various APIs and protocols Write efficient code and optimize database queries to handle growing transaction volumes Implement comprehensive test coverage (RSpec) and maintain high code quality standards Instrument code with proper logging and monitoring using our ELK stack Work closely with frontend engineers, infrastructure team, and product to deliver features that delight our clients You'll focus on backend, but you'll occasionally work across the full stack - we're a small team where backend engineers ship UI fixes and frontend engineers optimize queries when needed Requirements You'll need: Strong English skills; German is a plus Nice to have: Experience in FinTech, payment processing, or e-commerce Knowledge of background job processing (Solid Queue/Delayed Job/Sidekiq) Familiarity with ELK stack for logging and debugging Experience with Docker and containerized applications Understanding of security best practices for financial applications Benefits Learn from experienced Engineers: Influence product direction by working directly with clients like N26, Trade Republic, and major global brands Modern Development Practices: Attractive salary Berlin Lifestyle: Office in Charlottenburg with flexibility for hybrid work arrangements Ready to build backend systems for the next FinTech Unicorn?