CTO / Co-Founder

About 0TO9 & Our New Stealth VentureWe’re a fintech venture builder and investor – a bank for entrepreneurship. Our mission is to bring the right people, skills, and resources together so fintech founders can focus on building. From capital and compliance to tech and talent, we create an infrastructure for success.

We are launching a new stealth fintech startup and are looking for a Founding Product Engineer / CTO to build and lead the technical foundation of the company. The venture is already led by a CEO, and this role is designed as the technical founding partner.

The product is an AI-powered financial assistant for people under financial stress, helping them understand their situation, regain control of their finances, and move back to stability, a massive and largely underserved market.

As the Founding Product Engineer, you won't just be executing a roadmap, you will be creating it. You will own the entire technical evolution of the product, moving from a prototype to a scalable, production-ready platform.

Unlike most early-stage startups, this company starts with real infrastructure in place: access to licensed banking rails, regulatory setup, and the support of the 0TO9 venture platform. This allows the you to focus on building product fast and getting to market quickly.

• Architect and build the entire mobile product (React Native, TypeScript, Tailwind) and define the backend architecture and APIs.
• Build the core engine, from seamless onboarding and Open Banking (PSD2) integrations to AI-driven categorization and behavioral financial flows.
• Design infrastructure for secure handling of financial data (PII) with encryption and a compliance-aware architecture.
• Set up CI/CD pipelines, release flows, monitoring, and crash reporting to run a reliable production system.
• Work side-by-side with the CEO to turn complex financial data into intuitive, trust-based user experiences.

Who You AreYou are a builder at heart: curious, driven, and resilient. You thrive in the ambiguity of early-stage startups and take full ownership without needing layers of approval.

• You are a React Native expert (TypeScript/Tailwind) who thinks in user journeys, not just components. You understand that in Fintech, "Trust Design" is everything.
• You use AI daily to code, refactor, test, and debug, allowing you to ship significantly faster than traditional workflows.
• You are comfortable working across the stack, from mobile product experience to backend architecture and secure data handling.
• Whether you’re an ex-founder or a senior dev ready to take the leap, you move fast and embrace the "stealth" challenge.

What You Get

• Salary from day 0, and significant equity ownership.
• A venture studio team by your side, experienced founders, operators, and fintech specialists.
• Licensed bank infrastructure with the compliance, regulatory, and legal setup already in place.
• The chance to build something meaningful, not alone, but together with a high-bandwidth team in the heart of Berlin.