Fullstack Senior Software Engineer

Tired of working in predictable fintech environments where real ownership is limited and impact feels diluted? We are building something more ambitious — a new infrastructure layer for interbank communication .

Backed by leading investors, we are developing a SaaS platform that enables banks and fintechs to integrate secure, scalable interbank messaging and transaction capabilities with minimal technical overhead. Instead of incremental features, we focus on core financial infrastructure that connects institutions across Europe.

The Role

To execute on this vision, we are looking for an experienced Senior/Principal Software Engineer who enjoys building systems from first principles and taking end-to-end ownership across the stack.

You will join our core engineering team, responsible for defining the technical foundation of the platform. We operate with low hierarchy, high autonomy, and a strong emphasis on impact. The company is headquartered in Berlin and offers a remote-friendly environment.

The Opportunity

In this role, you will:

• Help design and evolve the architecture of a secure interbank communication platform.
• Build core infrastructure enabling reliable data exchange between financial institutions across Europe.
• Empower fintechs and banks to integrate advanced interbank messaging and transaction workflows through our APIs.

Tasks

• Strategic Technical Ownership : Define and drive the long-term technical direction of the platform, establishing core architectural patterns and engineering standards from inception through scale.
• Architecture & Systems Leadership : Lead critical architectural decisions, design distributed systems that operate reliably under high load, and ensure durability, security, and operational excellence at scale.
• Execution at Scale : Deliver complex, high-impact capabilities end-to-end, balancing speed with engineering rigor, performance constraints, and long-term maintainability.
• Engineering Leverage & Culture : Elevate the overall engineering bar by mentoring senior engineers, shaping processes, and cultivating a culture of accountability, technical excellence, and thoughtful collaboration as the organization grows.

Requirements

• We’re looking for a senior engineer with 8+ years of hands-on experience building and operating production systems — someone who is comfortable moving between product discussions and low-level implementation details without losing depth in either.
• You’ve designed and shipped robust APIs - REST or GraphQL. You think in terms of system boundaries, contracts, and long-term scalability. Authentication, authorization, and security models such as JWT and OAuth2 are familiar territory. Experience with event-driven systems (Kafka, WebSockets, or similar patterns) is highly valued.
• At the data layer, you are confident with PostgreSQL — from schema design and migrations to query optimization and performance tuning. You understand trade-offs in relational modeling and have worked with ORMs such as Prisma without becoming dependent on them.
• Cloud-native experience is a strong plus: deploying workloads on GCP (Cloud Run, Functions), building CI/CD pipelines (e.g., GitHub Actions), containerization with Docker, and orchestrating services via Kubernetes.

If you don’t check every box but have the depth and learning velocity to close gaps quickly, we would still encourage you to apply.

Who We’re Looking For

• You operate comfortably with high autonomy. You take ownership beyond tickets, care about details, and drive initiatives from concept to production.
• You value uninterrupted building time, prefer writing thoughtful code over attending status meetings, and measure progress by shipped, high-quality systems.
• You are motivated by working alongside strong peers who challenge assumptions, raise the bar, and are committed to building something ambitious and technically meaningful.

Bonus Points

Experience with additional languages such as Go or Java/Kotlin.

Strong understanding of microservice architectures and operating high-load distributed systems.

Background in fintech or early-stage startups is a great plus

Experience building products in regulated environments (e.g., fintech, payroll, tax, financial infrastructure).

Experience delivering embedded or white-label platforms used by third parties.

Benefits

Benefits

We aim to create an environment that combines the energy of an early-stage team with the stability and professionalism of a well-funded company.

Equipment of Your Choice
You’ll receive modern hardware tailored to your needs. Whether you prefer the latest MacBook or another setup that helps you perform at your best, we provide high-quality equipment in line with company policy.

**Flexible Work Setup
**You can work remotely or from our office in Berlin (Kurfürstendamm). The office is available for those who prefer in-person collaboration, while maintaining flexibility for focused remote work.

**Competitive Compensation
**We offer a competitive salary aligned with market benchmarks and your level of experience. Compensation is structured in compliance with applicable German employment regulations.

**Wellbeing & Lifestyle Benefits
**We provide access to Urban Sports Club membership and other employee benefit programs where available. Additionally, we may offer access to selected corporate perks and partner discounts.

**Small Team, High Impact
**You will join a focused team of fewer than 15 people, where individual contribution is visible and meaningful. At the same time, we operate with the financial backing and structural discipline typically associated with more established companies.