About the role

Senior Software Developer optimizing backend services using Node.js and MongoDB at a growing FinTech company in Köln. Focused on architecture decisions, mentoring, and team collaboration.

Responsibilities

Technical ownership: With Node.js and MongoDB at the core of the stack, you are responsible for developing and optimizing backend services. You won’t make architecture decisions alone, but you will actively drive them.
High-performance APIs: You design and optimize scalable interfaces to partner systems — with a focus on latency, reliability and maintainability.
Infrastructure & operations: Linux, Docker and Kubernetes are part of your daily routine. You keep systems stable and identify bottlenecks before they become problems.
Innovation: In close collaboration with other departments you work on new processes and design internal tools to optimize the system landscape.
Mentoring & team support: You share knowledge through code reviews, pair programming and honest feedback. You build a team, not just features!
Setting quality standards: You live Clean Code and ensure, through reviews and best practices, that the entire team benefits.

Solid foundation: A degree in computer science or a comparable qualification as the foundation of your expertise.
5+ years of backend experience: A significant portion of this experience with Node.js and MongoDB (or similar NoSQL databases) in production environments.
True ownership mentality: You don’t wait for tasks — you identify problems, prioritize independently and drive solutions to completion.
Expert knowledge: System architecture, networking and IT security are part of your daily work — you think in systems, not just in features.
Personal qualities: Strong organizational skills and high self-motivation for technical challenges.
Clear communication at all levels: You can justify technical decisions both in code and when speaking with non-technical stakeholders.

Excellence & ownership: Take full responsibility for your areas with a focus on quality, impact and sustainable results.
Purpose & scope to shape: Contribute your ideas, define your area of responsibility and help shape the future and long-term success of our company.
Openness and mutual respect: We promote open communication, direct exchange and collaboration on equal terms at all levels.
Continuous growth: Whether through training, cross-functional learning formats or individual mentoring, you’ll continue to develop professionally and personally.
Flexible working and shared celebrations: We offer benefits that make a difference — workation options, team and company events, and subsidies for lunch, internet and the Deutschlandticket help you focus on what matters.
Equal opportunity: Not a buzzword but our stance — we welcome applications regardless of background, identity, sexual orientation or disability. If equally qualified, applications from people with severe disabilities will be given special consideration.